312. How Blood Volume Impacts Performance and Adapts Fast, The Scary Potential of Lactate Supplementation, The True GOAT, and The Circle Pit!

Summary

Some Work, All Play — Episode 312: How Blood Volume Impacts Performance and Adapts Fast, The Scary Potential of Lactate Supplementation, The True GOAT, and The Circle Pit!

Hosts: David Roche & Megan Roche, M.D.
Release Date: May 26, 2026

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Episode Overview

This episode delivers a trademark blend of enthusiasm, deep science, and personal storytelling, as David and Megan Roche take listeners on a journey through topics that include blood volume’s profound effects on endurance, the possible implications of exogenous lactate supplementation in sport, a lively debate about the “greatest of all time” in endurance, current running news, and surprisingly passionate asides about hospital stays and pump track races. The show opens with a heartfelt update on Megan’s cardiac health and both hosts’ evolving mindsets, and then dives into some of the hottest—and most controversial—science and cultural debates in the running/endurance world.

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Megan’s Cardiac Journey & Life Updates

[00:00–09:27]

• Joyful Mood and Health Update: Megan opens the podcast with infectious positivity, revealing after a tense period with her heart that her EKG finally normalized. A deeply personal discussion follows of her recent hospital stay, the trauma and uncertainty that lingered, and the powerful feeling of “believing” through adversity.

  “The biggest thing that I've learned in this time is that it's just so much more fun to believe.” — Megan (06:39)

• Processing Possibilities: Both discuss the emotional journey—Megan honestly contemplated and became “somewhat okay” with a future without competitive running, and David’s openly shared how her vulnerability and courage helped him process vicarious anxiety (leading even to his own heart palpitations).

• Adaptation, Family, and Mutual Support: The exchanges underscore themes of mutual care: David discusses the emotional toll (“my PVCs are starting to dissipate, which shows how happy I am”), while Megan discusses her commitment to better listening to her body and prioritizing long-term health, for herself and her family.

• Joking & Real Talk: They keep their signature lightness, joking about David’s inability to give Megan her injection and the oddities of their hospital “Airbnb” experience.

• Roadmap: David quickly outlines key science topics: blood volume, Enhanced Games controversy, exogenous lactate, fueling updates, uphill treadmill training, and GOAT discussions.

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Deep Dive: Blood Volume and Its Impact on Performance

[09:46–41:15]

What is Blood Volume?

[16:10–17:05]

• Blood volume combines red blood cell (erythrocyte) volume and plasma (mostly water + proteins, glucose, electrolytes, etc.)
• Difference between “blood volume” (includes RBC) and “plasma volume” (without RBC), both crucial for performance.

Core Principles and Key Research

• Increases with Training ([17:05–17:39]): Just 7 weeks/3 sessions per week of running intervals yielded significant plasma volume increases in male subjects.

  • Plasma volume rises quickly, RBC and hemoglobin mass follow with more weeks.
  • CR Meter Hypothesis ([17:50–18:17]): David revels in this concept, describing it—as on past podcasts/dinner tables—as the sequence by which training increases plasma first, with the body eventually boosting red blood cell mass to catch up.

  “When you start any of these interventions... your liquid content in blood increases ... and the body senses the need for more blood volume because that fuels training.” — David (18:03)

• Detraining = Rapid Losses ([22:24–23:30]):

  • 12% decrease in plasma volume after 1-2 weeks’ inactivity; parallel drops in stroke volume and VO2max.
  • Heart rate can immediately rise ~11% due to lower preload.

  “Maybe those are almost synonyms, blood volume and fitness.” — David (23:30)

• Manipulating Blood Volume: Rapid reversibility in studies: saline or dextran infusions (now banned) can immediately “restore” lost plasma volume and fitness; blood draws reverse weeks of adaptation.

Altitude, Heat, and Sex Differences

• At altitude, plasma volume can drop 6–9%, while red cell mass increases (explains some “responders” vs “non-responders”).

• Heat Interventions: Studies show sauna post-exercise (e.g. 30 mins) can raise plasma volume by 10–18% in days. Notably, the famous 17.8% increase after just 4 exposures (27:45–29:01).

  • David repeatedly hypes “year-round heat training”:

    “If that's true... this is the thing that everybody needs to be talking about all the time. What else in the human body changes almost instantly?” — David (28:00)

• Sex/Gender Effects: Men have higher blood volume at baseline; menstruation, period blood loss, and blood draws disproportionately impact women’s athletic adaptation.

• Seasonal Variation: Plasma volume decreases up to 15% in colder months without heat exposure.

Real-World Advice (Stacked Protocol for Athletes)

• Maintain consistent training (regular aerobic stimulus keeps blood volume elevated)
• Incorporate heat—sauna, hot baths, light jackets, or even moderate passive heat post-workout, particularly valuable during taper, rest, or detraining ([35:35])
• Hydrate and replenish electrolytes—especially at altitude and in heat.
• Iron & Energy Availability: Megan warns that heat + sweat = iron loss; low iron or RED-S can critically limit ability to expand red cell mass, “the most likely explanation” for low hemoglobin in many (controversial take at [32:09: “86%” of athlete labs she sees, it's under-fueling!]).
• Dose-Response: Even 1x weekly 20-30 minutes’ heat post-exercise may produce large effects—young researchers invited to study this! ([38:32])

“If you don't have clean sport, you don't have sport.” — David (53:34)

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Science Snacks

Exogenous Lactate Supplementation: The Next Frontier (and Its Dilemmas)

[58:23–64:47]

• Context & Concern: New studies (led by luminary George Brooks) explore exogenous (supplemental) lactate as both fuel and signaling agent. Megan expresses both scientific excitement and “existential” sadness at how this could change endurance sport if abused (“a pay-for-lactate playing field” [59:04]).

  • Lactate is not just a waste product, but a primary fuel, glucogenic precursor, and signaling molecule (myokine/exerkine)—making it potent for both performance and recovery.

• Medical Promise: Could be revolutionary in traumatic brain injury (TBI) or other disease states by providing energy to brains with impaired glucose uptake.

• Ethical Edge: Hosts agree: until safety, legal status, and accessibility are clear, they’ll wait. Megan: “Ethically, it feels a little bit weird until we have more data on it...” ([63:19])

• Peloton Paranoia: Is it already in pro cycling? Unclear, but listeners are invited to send (confidential) tips!

• Big Picture: The field is changing fast; Brooks’ lab is breaking new ground in making stable, bioavailable lactate formulas.

  • Stay tuned: “My guess is this is a big topic of conversation over the coming years...” — David (64:49)

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News: Enhanced Games, Cam Haynes Doping Controversy & Circle Pit Discourse

[41:15–57:33]

The Enhanced Games:

• A hyped, non-sanctioned meet inviting “enhanced” (PED-using) athletes for direct competition—meant to “show what’s possible” if drugs were allowed.
• Results? Non-enhanced athletes still dominated sprints; the spectacle was lampooned as a “big wet... slow fart.” Both see little threat to clean top-tier sport, but acknowledge the persistent risk of normalizing doping cultures:

  “If you don’t have clean sport, you don’t have sport.” — David (53:34)

The Cam Haynes/USADA Debate:

• Prominent athlete Cam Haynes publicly discussed using banned substances, and raced/medaled in age-group marathons.
  • Hosts emphasize the importance of rules: “If you’re going to compete in sports, that is a privilege, and you need to follow the rules...” — David (50:16)
  • Both express compassion for aging athletes, but warn against slippery slopes that could undermine clean competition for all ages. Therapeutic Use Exemptions (TUEs) are touched upon, but Megan notes practical barriers for the average competitor.

Circle Pit & The Satisfy Controversy:

• The “Satisfy Circle Pit” event—runners looping a pump track to live metal music, in ultra-expensive kit—sparked viral (mostly negative) reaction online.
  • Megan’s hot-take: “I would actually love to run around a pump track for 20 minutes. That actually sounds like a genuinely fun, athletic event.”
  • They call for less shaming and more joy:

    “Let people have fun... It is not a personality to hate things that people like.” — David (56:23)

  • Both agree: If it were $20 shirts, there’d be less hate; but the internet loves dunking on joy.

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Other Notable Science Topics

Carb Fueling: Brief mention of a new study—combining multiple carb sources (glucose + fructose) for better uptake is still strongly advised ([65:24]).

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Listener Q&A Highlights

Q: Who’s the True GOAT of Endurance?

[66:44–68:08]

• Lively debate on cross-sport (marathon, cycling, triathlon) dominance.
• Tadej Pogacar (cycling) takes their “King of Endurance” crown for men; women’s pick likely a runner, due to sport access/funneling.
  • Blumenfeld gets a nod for highest VO2max but less outright dominance.

Q: Is Running or Biking Harder to Excel At?

[68:29–69:20]

• Both argue running is harder to master due to injury risk and the years-long process of building biomechanical resilience.
• Cycling offers lower mechanical stress, so pure physiological “monsters” can rise more easily.

Q: Uphill Treadmill Threshold Sessions?

[71:11–73:12]

• Both wax poetic on the value of “5x10 minute” climbs for massive aerobic gains with minimal impact.
  • Uphill treadmill is a “gateway” to safe fitness, and is built into their long-term base-building plans.

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Running Jokes, Listener Love, and Sentimentality

• The episode is rich with upbeat banter (from failed hospital injections to catfish cuisine gone wrong), running in-jokes (“Stroke output” vs “cardiac output”), and loving jabs at internet trolls and expensive running shorts. There’s tongue-in-cheek self-censorship and meta-riffs on their own podcasting style.

Standout Emotional Moment

[74:56–77:03]
David reads his chapel note from the hospital:

“Megan, I love you to the moon and back. You carry my heart, and no matter what, I pledge to carry yours.”

They share a moving reflection on hope, resilience, and the miracle of existence in both athletics and life:

“Being an athlete is beautiful for that, because it’s just an act of radical hope every day, especially with age.” — David (82:09)

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Timestamps for Key Segments

• 00:00–09:27: Megan’s heart update and philosophy of “believing"
• 09:46–41:15: Deep dive: blood volume adaptation and practical takeaways
• 41:15–57:33: News – Enhanced Games, Cam Haynes, Satisfy Circle Pit
• 58:23–64:47: The science and ethics of exogenous lactate supplementation
• 66:44–73:12: Listener Q&A – GOATs, running/biking difficulty, uphill treadmill
• 74:56–77:03: Emotional reflection – hope, love, and believing through adversity
• Throughout: Humor, asides, and plenty of joyful riffing

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Memorable Quotes

• “It's just so much more fun to believe.” — Megan (06:39)
• “Maybe those are almost synonyms, blood volume and fitness.” — David (23:30)
• “If you don't have clean sport, you don't have sport.” — David (53:34)
• “Let people have fun... It is not a personality to hate things that people like.” — David (56:23)
• “Being an athlete is beautiful for that, because it’s just an act of radical hope every day, especially with age.” — David (82:09)

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Final Thoughts

This episode is a quintessential mix of deep science (notably blood volume and emerging performance tech), empathetic coaching philosophy, and unfiltered joy. Megan’s health saga is both sobering and uplifting, and the nuanced stances on everything from doping to fashion controversies frame a values-based approach to sport. There’s actionable training advice, especially around blood volume and heat, for athletes of all levels—and, as ever, there’s love, laughter, and a call to radical hope.

Transcript

[Megan]

Woohoo.

[David]

Welcome to the Stomwork All Play podcast. We are so happy to be with you today.

[Megan]

Happy Tuesday. It's Tuesday and I can't stop grinning on this Tuesday.

[David]

Oh my goodness. I know where this grin's coming from.

[Megan]

It's lighting up right now. Can't stop.

[David]

Best vibes ever to start a podcast. So if our listeners have been around for a little bit. Megan's been going through heart issues for five years now. It's been such a journey. You've been so courageous through it all and you've told your story through it all. And two weeks ago, you described your most recent trip to the hospital, your three day stay at the amazing Airbnb Boulder Community Health.

[Megan]

Yeah, Boulder Community Hospital really kind of is like an Airbnb. It had catered food actually, that goes above and beyond an Airbnb. Even had a toothbrush for us. The perfect kind.

[David]

Yeah. Honestly, when you have two small kids, it's a great getaway.

[Megan]

You know, I thought about that for a minute and then I was the one that was being woken up every three hours to my troponin blood draws and I was like, get me out of here.

[David]

It was pretty nice for me is what I'm saying.

[Megan]

At first it was like 9 o' clock at night and I was reading a book in bed and I was like, gee, this is peaceful. And then they came in over and over and over again and I'm like, you know, not so much.

[David]

And when your heart goes different VTAC in the corner, it's not necessarily a fun thing. And you're having 8 million PVCs and all that. So let's give them an update. You'll. You can take the reins here, Megan.

[Megan]

I got good heart news. Last week my EKG normalized, which was awesome. I did so many tests and I feel like I was waiting for them. They took a long time to come back.

[David]

Yeah, it's just so remarkable. So three weeks ago we were in the hospital and you know, I was there with you. As the doctor said, you don't just need to retire. You're probably never going to run again. And this was before a number of tests were being done and the assumption was that some of these tests would come back bad with findings just given

[Megan]

the, like, the trajectory of some of my troponin levels and EKG and everything that happened. It was like clearly my heart was not in a good place.

[David]

Yeah, if this was a show of Dr. House, it would be girl fucked. And you know, you were so open and that's how we recorded that episode, basically is this understanding that this could be a long term, end of your career type situation, which I don't love

[Megan]

doing at the same time because I'm like, I don't want to scare people,

[David]

you know, Megan, I was in the hospital with you. I've been in these cardiology appointments with you over time too. It's not the first doctor that's told you to stop.

[Megan]

I know, but it's like I feel like by living that story as it's being told, it's like all these podcast listeners are also waiting for my, like, you know, follow up ekg, my blood results and all of that. And I don't want anyone to have to be on that waiting, scary journey with me. And I'm like, I'm sorry.

[David]

No, that's life. It takes so much courage to tell your story while you're going through it because it's not like you're healthy now. You still have a major heart condition. You were still injecting yourself in the stomach with your new heart medication. All that it is is that the worst didn't happen. And we were in a moment where the worst seemed like a 95% plus chance based on all of the probabilities we're given. So you got a cardiac MRI back, which came back without myocarditis, which shocked the doctors. Everyone was just totally stunned.

[Megan]

I was convinced because I had it in 2021 and this felt very similar. The test results were similar. And I was like, I have myocarditis.

[David]

Just what they thought too.

[Megan]

And I was just. I honestly fully processed it until I got the cardiac Mr. Results back. And then it was clear and I was like, what the fuck?

[David]

Zipping back. That's the part that conf me the most. Were you in shock? Because in the moment you were just so open to it. Like, you're just like, this is my reality. This is what we're going to do. I'm going to start climbing. I'm going to be a knitter. It's going to be so bad. Or pottery, actually, not knitting.

[Megan]

I was excited. I was like, we're going to put a ceramics wheel in our barn. This is going to be great. I'm going to embrace pottery. I know. I truly processed it. I was like, what would my life look like without running? You know, I got to the point that I was somewhat okay with it. You know, I missed the day to day endorphins. I just took three weeks off of no training and I just became more peaceful with it in time. But I really do miss those day to day happens.

[David]

And then the heart cath came back with the best arteries they've ever seen. Just pretty nice to hear. And then finally you got a normalized ekg. Because the scariest thing of all was when you went into the er, you had biphasic T waves. The Welland syndrome we've talked about. Everybody out there, don't google it. It's not fun. And the fact that that normalized. And the doctor who has given us much of the scary news that we've had and has been the most against your running over time came into the room and said, this looks like a normal heart.

[Megan]

And I was. Normal heart with pericarditis. Yeah. Yeah.

[David]

Well, no, not on the ekg.

[Megan]

Yeah, on the EKG actually looked good.

[David]

That's the point. His point was that on the EKG

[Megan]

it looked like that it got a lot better over the last couple of weeks. And so to go into that appointment and to have that normal EKG last week and just to have things feeling good, I was like, what is happening right now? And so we had that appointment on Wednesday. And then Wednesday night I woke up, I'm like heading into Thursday morning at 3am and I just could not contain my excitement to go for a 30 minute run. It was like so beyond excited to do that.

[David]

And we hung out a little bit because I couldn't go to sleep with my rapid PVCs. I was having heart issues. Just, you know, premature ventricular contractions. A lot of people have them. Um, but I think it was because I had such a severe stress response in the hospital, expecting that those results would come back like a lot of the others did. And so, you know, it shows just how much you've been through that. I'm getting them from sympathy at this point.

[Megan]

Even on good days, maybe they're contagious.

[David]

True. And so you got back to jogs. Probably felt like a big old bag of dicks, but you did it. And it's so exciting. And so, yeah, there's a long road. Here you are taking a new heart medication that gives you hope.

[Megan]

I injected myself with it. That was quite the process.

[David]

I was going to inject you. I was so pumped. I was getting hyped. You know, I'm not a needle guy, but I'll do this for my girl. And then as soon as you saw me handle a needle, you're like, nope, you are not doing that to me.

[Megan]

We had a whole chemistry experiment. We had to like reconstitute the meds, which means mixing, like, powder with the saline, and then went through this whole process of changing needles. And as I was watching you do this, I was like, you are absolutely not going to inject me.

[David]

I respect that.

[Megan]

I trust you with a lot of things. I really don't know if I trust you with a needle. And so I injected myself. I've never injected myself with anything before. Yeah, I'm not going to lie. Like, you know, done injections, obviously, like, in med school, it was a little trippy doing it on myself.

[David]

Yeah, it looked pretty horrifying.

[Megan]

Yeah. It was also a big volume of fluid to go subcutaneous. And then I had this, like, lump after, and I kept staring, and I was like, is that normal?

[David]

Yeah. So it could be the first day of the rest of your life, or it could be back in the hospital. We don't know. But for now, you know, holding on to hope. And so thank you all for being here and also sharing your stories. We got a lot of messages from people that have gone through their own uncertainty. And, you know, this is not a happy ending. This is just a continuation with a moment where we're going to be grinning our asses off, because that's life, right? Like, you know, we zoom out long enough, and this is probably going to be a tougher story, just because that's all of us are facing that. And so, Megan, just seeing you go through it is the coolest, most fun thing. And I'm just so, so happy. And, I mean, my PVCs are starting to dissipate, which just shows how happy I am.

[Megan]

Well, I think for me, too, the biggest thing that I've learned in this time is that it's just so much more fun to believe. I think that's where I am right now, is there is a lot of uncertainty, and I'm in this very hard gray area of, you know, now I have to commit and I have to promise myself, like, this is for Leo, for Ollie, for you, for myself now and myself in the future. And, like, I have to take two weeks off of running anytime I have chest pain. And, you know, I've trained through a lot that I've just kind of written off. It's a very hard gray area. When you return back to running as to, like, you know, I feel this sensation, like, is this my heart? Is this my chest? Is this something else? And I think I need to take it a lot more seriously now. And, you know, that's a hard place to be. But I think through this whole process, I Also want to commit to believing long term because it's so much more fun.

[David]

Well, I'm going to be believing so hard for you. And honestly, Megan, I, who runs through pain. What are you doing? I'm so disappointed in you. As I go down to scratch my foot, which is currently in a booth,

[Megan]

it's hard to be an athlete. You know, it's like, I think sometimes, like, as an athlete, you do push through a lot of things. And I think for me, sometimes over time, this has been 5 years of chest pains, that some have been pretty insignificant, some have been more significant, and it's really hard to know what's what.

[David]

Yeah, well, for now, there's so much hope, and this is going to be the best celebration episode ever. So let's get right to it. Quick roadmap. We're going to start with a big breakdown of an overlooked training element, blood volume. Then a news discussion on recent controversy, including the Enhanced Games. Maybe some talk about Cam Haynes and how that's related and the satisfy Circle Pit. Then the weird new world of exogenous lactate. That could be a scary one. Also an exciting one. This might be the new frontier that we're not hearing about yet. Who knows?

[Megan]

I felt kind of some existential sadness as I was reading through the science on this, and what could happen if we start delivering lactate to athletes in the middle of a workout, in the middle of an ultra, how that could fundamentally change the endurance world. And then I was like, are athletes doing this right now? You know, that's a big question that I have.

[David]

I like how open you're making this. We know the answer to that.

[Megan]

Yeah, well, I mean, we have decided

[David]

not to engage with this yet. And it goes based on some of our understandings of this world, where there's two steps. One is whether something is legal, which it is. The other is whether it's publicly available. Which is why when this study comes out, we're like, okay, now this is exciting. We can start talking about it, hearing about experiments, maybe even piloting some ourselves. But for me, at least until the study came out, I was a little bit more hesitant because this was all whispers. This is one of those things we've been alluding to. If you've been listening very intently to the podcast recently.

[Megan]

Well, I guess my brain is going. It's like, what happens if we have exogenous lactate and bicarb and Gnomeo? It just kind of scares me. I don't love this direction of sport.

[David]

Same, maybe even move that above the campaigns Type stuff, but we'll see. Um, then combining glucose and fructose fuel sources. A new study into Q and A on running versus biking, the uphill treadmill. The true goat and lots more.

[Megan]

There's a lot of good stuff on here. I'm very excited though, for the deep dive on blood volume. I started going through the science this morning and I was like, ooh, this is good. It's a combination of, like, physiology mixed with real world application of what happens when we combined, you know, thinking about blood volume with heat with altitude, how we stack that together. And so I'm excited for it and

[David]

it all starts to fit together with training theory generally. So before we get to that, a quick promo for the feed. Go to the feed.com swap S, D, Y, P. Your first order, 40% off. Every other order, $10 back for every $100 spent. It is so good. And there's a Memorial Day sale right now. You have to go. I think it's going to be lasting all week. Everything is doing great. Main thing I want to promote science and sport. Beta fuel gels are in major stock right now and are pretty darn cheap at the moment. So got to check those out. Scratch hydration. That's awesome. Garmin watches. I think I have a 965 here. It's amazing how long these batteries last.

[Megan]

It's true. I know. Especially when you're not training. I'm like, I need to charge my watch once, like every two weeks, even when training.

[David]

It's like once every week now. Whereas in the old days I used to have to do it every day. Just truly bonkers stuff. And then here's just a message from a listener. Tove Alexanderson just posted about using both Gnomeo and bicarb the morning of Zegama, where she set this massive record. And over 100 grams of carbs per hour. That probably speaks for itself. And she's sponsored by both Nomeo and Martin. This should. There should be a study on this. So, you know, Tove is one of the greatest of all time. She's on top of this game that we're trying to tell you about. And I think that that just shows almost everyone who's truly at the top of the game now is doing this. But this is available to everyone. Gnomeo, bicarb carbs. This is where it's at. Get it at the feed.

[Megan]

I didn't realize Gnomeo was directly sponsoring athletes. And I love that. It's like, you know, get behind the game of Big Broccoli.

[David]

You Love that for them.

[Megan]

I love that for them. Yes.

[David]

I always come back to. But Gnomeo, they're such a open minded company. They reached out to me last year way before they were the Gnomeo that people knew about. And just like, how many can we send you? I was like, oh, you know, maybe send them to us. But I was so skeptical because it's broccoli. Broccoli doesn't do shit.

[Megan]

You're like, I don't believe in vegetables. At baseline, you're anti vegetable.

[David]

I'm not anti vegetable.

[Megan]

Unless it's for our children. And then you just get, you get targeted by vegetable signaling and you go down that pathway.

[David]

The vegetable marketing that they do to kids that are just chips. But they sent an amount of Gnomeo to our house that in retrospect is worth like more than our house.

[Megan]

Actually. That's belief in the product.

[David]

Yeah, yeah. And sure enough, we're still going through it. And I've recently looked up how long it takes them to go bad and maybe we should get a new shipment. But this stuff's legit, so go get some Gnomeo now.

[Megan]

I missed it, actually. I'm back on the Gnomeo train. As I'm like easing back into training. I honestly genuinely miss the taste.

[David]

I think it activates the mitochondria.

[Megan]

Yeah, I could use, I could use every activation right now.

[David]

Yeah, I mean they just, when they isolate muscle fibers and test tubes outside of, you know, what do they call that? Post or ex vivo? Ex vivo.

[Megan]

Oh, yeah, ex vivo. Oh, boom, boom.

[David]

Off top of my head. That's pretty, pretty good for a non scientist.

[Megan]

It is good, but every time I think about ex vivo, I'm like, oh,

[David]

well, you can also just develop this in the, in the test tube they see enhanced mitochondrial development, which is the coolest thing, like from broccoli sprouts. What? Okay, so get that at the feed. Now let's go on to blood volume. This is gonna be a big discussion and it is extremely relevant to you, Megan.

[Megan]

My blood volume right now is terrible.

[David]

It's getting better. It's probably already way, way better.

[Megan]

It's getting better by the day. But I went for my first run and I didn't look at. You know, sometimes when you're having a heart issue, you don't wanna like directly stare at your heart rate because it's tricky. It's like, you know, and that's the hard part I have me right now is like, you know, what's a medication side effect? What's coming off after three weeks off what is a heart signal? And it's really hard to tease apart. But I was joggin was looking down at my heart rate and I was being like, what is happening over here? It is high.

[David]

It is probably a combination of a lot of things.

[Megan]

Yes.

[David]

But based on the studies we're going to talk about, most of them likely converge onto blood volume and how blood volume is related to cardiac stroke outlet. So stroke volume of the heart and the world of blood volume. What's so interesting to me is this is probably the most important signal for fitness. Like, if we're just isolating one, because increasing blood volume immediately increases in VO2 max, increases your output increase improves your health overall. Like, will decrease your resting heart rate. All this.

[Megan]

And it has a direct relationship with heart rate and exercise because cardiac output equals heart rate times stroke volume. And stroke volume is a result of blood volume. Um, and so to me, that equation is like, everything.

[David]

But it's so weird that people aren't talking about it. Like, I've been thinking about this forever and, you know, I think what. One of the tricky elements here is that a lot of the cheating methodologies of, like, the 2000s or the things that we're gonna talk about in the enhanced games are designed to attack the system. So talking about it at all makes people be weird. But the point is, almost all of it is natural variation. And you can make this so much better almost instantaneously. It's. It would be like if you could stuff six months of training into a week and get the benefits of that. It's like, that's why it's so cool.

[Megan]

And I think there's a lot of relevance for what happens when you detrain as well.

[David]

Yeah.

[Megan]

And you know, in a period of. Of time that you're off training, heat interventions can actually be really helpful. And this is where, like, I just took three weeks, was fully off of training, but couldn't do heat. And that's where I was like, I feel like my blood volume and it definitely did just plummeted.

[David]

And you had a lot of blood taken from you.

[Megan]

Oh, true. I know. It was coming from every angle.

[David]

I think that's the biggest problem. And you had your period in that time twice. Oh, my gosh.

[Megan]

Yeah. It's rough. It's coming out every hole, every orifice.

[David]

No. And it's one reason that women and men have performance differences at baseline is like, the average man will have much higher blood volume. And you look at many.

[Megan]

That's outside of the menstrual cycle. That's like. That's broader physiology.

[David]

Oh, yeah, for sure. But the menstrual cycle doesn't help with blood volume changes. You know, it's one of the things we talk about with like, you know, choices of whether IUD or other things. And I mean, for me, probably my biggest advantage is I likely have a large, a naturally high blood volume reservoir.

[Megan]

You're a blood volume boy.

[David]

Yeah. And it's interesting because I coach a lot of athletes that run for these shoe companies, and almost all the shoe companies are now doing retreats. You probably see these on Instagram, where all the athletes go run together and post these, you know, delightful whimsical reels that look like summer camp. But in that process, they have physiologists there and they're almost all now doing blood volume tests. So not just your normal hemoglobin, hematocrit, they're doing carbon monoxide rebreathing to measure total blood volume. Um, and. And that's really interesting that they're seeing that signal and taking this world of professional cycling, which has been doing this forever, and now we're doing the same with trail runners. It's just a really interesting time that I think we're starting to think about this subject so much more.

[Megan]

Why do you think it hasn't been talked about, like, prior, though? I feel like this is like an expanding area. But do you think it was just because people just, you know, there's other byproducts that we can think about in physiology. And even though this is a massive one, it just kind of got overlooked for, like, you know, other measurements. Whether we're thinking about, like, you know, classic lactate measurements or, you know, and that can be a proxy for blood volume. Like, do you think we were looking at other proxies?

[David]

I think people were talking about it to a certain extent behind the scenes, but it wasn't the type of thing that was trickling down to everyone because, you know, the elite athletes are often gifted with this, and that's one of the elements of talent that we just see right away, even though we're not identifying it. And they have time, so they're doing all these extra things and it's just something that incorporates into their world, whereas everybody else is just not. And why. It's why we've been so at the front end of things like heat training, because this is the lowest hanging fruit in development. So let's get into it. We're gonna start with just a basic definition here. So blood volume is the sum of erythrocyte volume, which is red blood cells, and plasma volume, which is mostly water, plus some dissolved proteins, glucose, clotting factors, electrolytes, hormones, et cetera. So basically, the easy way to think about it is red blood cells plus, like, liquid content of blood, mostly water.

[Megan]

And you'll see it in research in two different ways. Blood volume, which includes that red blood cell addition, or plasma volume, which is the volume without the red blood cell addition. And they're both very similar, obviously.

[David]

And so let's just shoot through principles that will bring us to a unified theory of blood volume. First one here is that it increases with training. It goes up just with training, which might be one of the reasons it's not talked about that much, is that training consistency is the easiest way to address this partially, but it doesn't address it fully. Uh, so there's a 2013 study called Running Interval Training and estimated plasma volume variation, which did 15 men with seven weeks of training, found pretty substantial increases in plasma volume with improvements in fitness. Um, and there seems to be a time duration component here where plasma volume goes up first, followed by red blood cells.

[Megan]

And this was not with a ton of training either. So they were doing three days a week of running interval training, which isn't a lot in the grand scheme of things. And to see that increase in plasma volume in that time, I think is a really cool, cool part of science.

[David]

Yeah, absolutely. And this points out the plasma volume, red blood cell relation. The crit meter hypothesis. We talk about this constantly.

[Megan]

Okay, that tickles you. I like the CR meter hypothesis. Talk about it at a dinner table. And David is like, what's happening here?

[David]

I've been obsessed with this ever since I first heard it because it's so weird and cool and no one talked about it enough. I was on Rich Roll podcast, just going all ham on crit meter.

[Megan]

Did you actually say crit meter on Rich Roll?

[David]

You better believe it.

[Megan]

You said crit meter and suck it. Peter Attia, you are so 2026.

[David]

I think we're far enough away from that terrible disaster that we can joke about it now. But saying suck at Peter Attia and back in 2024 on ritual was probably my one moment where I'm like, am I a God?

[Megan]

I wonder if Rich has thought about that. And he's like, remember that podcast with David Roach?

[David]

Yeah, but the idea being that when you start any of these interventions, so in this case, just training, your liquid content and blood increases. So. So when you're doing it just from training, it could partially be from core temperature elevation, but it's likely just because the body evolutionarily senses a need to have more blood volume because that fuels training. So plasma volume goes up first. And another study found that in studies less than 12 days, there was an 11% increase in plasma volume, but no change in red blood cells. And then over time, the body sense the senses the offset in hematocrit. So the percentage of red blood cells goes down as the plasma volume increases and increases red blood cells. So studies longer than 21 days found a similar plasma volume increase, but a 9% increase in red blood cells. So it's just compensating for the offset increased by the plasma volume expansion.

[Megan]

And that's why it's important to do these blood volume studies both on different timescales. So measuring it at two weeks, four weeks, six weeks, and seeing what you see in terms of the change in plasma volume and then also the change in hemoglobin mass as well.

[David]

And we're about to talk about heat studies soon, which, you know, if you've listened to this podcast, echo that a lot. But before we do that, maybe the weirdest part of physiology and something that is extra tricky as we talk about what Megan just went through or what I'm probably gonna go through as my foot is sitting here in its little boots.

[Megan]

Yeah, I feel for you, man. You've had a journey with this foot.

[David]

I've had such a journey. This is one of those moments of. It's like a reflection on, you know, aging stupidity.

[Megan]

I mean, I think yesterday you were talking. You're like, megan, I like, feel a lot of shame, actually, about this, of the fact of, like, you know, trying to come back too fast on a foot. And this is how you've, like, been your whole athletic career. You've run through a lot of things. Like, you know, you have had different healing timelines, and you've come back pretty aggressively. And quite frankly, it's worked. Like, think about you coming back after your traumatic brain injury on the bike. Like, you came back well after that. And, you know, I think all of the data was pointing in this direction, and this is the one time it didn't work. And I feel like it's like, you know, you're going for it at almost age 38 and trying to do things to put yourself back on competitive starting lines. And it's like, sometimes you just gotta give yourself grace for that.

[David]

And I did say I was going for it with eyes wide open, but I had a relatively therapeutic moment this weekend where I was riding the bike. And I'm gonna actually stop riding the bike this week and really just shut down to see if I can get this fully healthy.

[Megan]

Well, I think it is kind of fascinating that, like classic planter fascia studies, like, you should be okay riding the bike, but I think you're in a different bike context because you're just too good.

[David]

No, no.

[Megan]

Put out too many watts.

[David]

That's not it at all. I think my plantar is just too damaged.

[Megan]

No, I think those studies aren't looking at athletes that are putting out 350 watts out of the saddle.

[David]

You know, I don't think it's that, but it was listening to could have Been Me by the Struts, which was a little bit of an anthem for last year. And I think everyone thinks of that song like, I don't want to. I'd rather wake up in a blaze of glory or things like that. Like the lyrics of that song to mean, okay, now go for it. But they never think about the other end of that song, which is it also says, you're going to go out in a blaze of glory sometimes. And you know, I push the limits, but I'm kind of proud of myself at the same time for going for it, you know. And yeah, the unfortunate part is just I wish I didn't have to cut, you know, face this. I'm like stuttering with going through this because it's just hard to understand, you know, what this can mean for the rest of my athletic career. But one step at a time.

[Megan]

Is that the hardest part you think is like projecting it forward or is it projecting it backwards on, like decisions like.

[David]

Yeah, or both projecting it backward, you know, just shame that I made the decisions I did, but at the same time, I wouldn't be who I am without going for it.

[Megan]

Yeah. But I feel like sometimes the best path of shame is just setting it free and being like, I'm going to talk about it, I'm going to joke about it, I'm going to laugh about it, and we're going to move forward

[David]

and I'm going to get great blood volume in this time.

[Megan]

You really are. You're going to do the heat training.

[David]

Yeah, because I'm going to counter what this next principle gets to. So the blood volume decreases rapidly with inactivity. So a study called Effects of Detraining on Cardiovascular Responses to Exercise Role of Blood Volume really looked at this in detail. It found a 12% decrease in plasma volume after a week or two. So you're seeing the Same reduction that counters the increase in the training studies, you're seeing that same 10ish percent decrease.

[Megan]

And again, plasma volume matters because it's an indication of how much blood is returning to the heart. And so when you think about that, that means that there's like, when you have that higher plasma volume, you're having higher preload to the heart, and that is thus causing higher stroke volume, which is contributing to larger cardiac output. And so if you're dropping that stroke volume part of the equation, your heart rate often ris in a compensatory fashion to keep the cardiac output, you know, trying to like, preserve that. And that's why in the study actually found that heart rate rose 11% after these athletes were detrained. And so that's very similar to what I'm experiencing this weekend where I'm going out and jogging. I'm detrained now, and I'm looking down at my heart rate. I'm like, gee, my RPE feels easy and my heart rate is doing crazy things. And that's a reflection, most likely of this equation.

[David]

Yeah, stroke volume decreasing by 12%, VO2 max declining by 12 or 6%. That's pretty darn substantial. Um, but the weirdest part of this study is when researchers reversed changes with a saline injection. So giving you more blood volume, the fitness changes reversed partially. So you're seeing that just enhancing that volume signal is the fitness signal. Maybe those are almost synonyms, blood volume and fitness.

[Megan]

And this was actually, it was the dextran in the saline. Did you catch that? So that's actually, it's really cool. It's what they use is it's like a large sugar molecule that essentially stays inside the bloodstream and that pools water into blood circulation. Um, and so I was like, oh my gosh, that sounds like a ped. And it actually is banned because if you think about it, it's like a plasma volume expander, but it only lasts on the order of like days to hours to days.

[David]

And it probably is one reason that injections generally are banned above a certain volume. Like, I think it's 125ml. So almost any injection you're going to get that's rather large requires some sort of tue for.

[Megan]

But it's kind of wild to have that data point of having the dextrin and saline injection like, like changing the blood volume response on a rapid order of time and seeing the athletes then have better, you know, heart rate metrics, better performance metrics. And that to me, I was like, this is Wild science.

[David]

Well, let's get into an even wilder one. So there's a 2014 study that did six weeks of training and it increased blood volume by 7% and VO2 max by 10%. So similar levels there. Um, but here's the wild part. Everything went to pre training levels after a phlebotomy, returning their blood volume back to baseline. So you can train, train, train, get stronger, stronger, stronger. But as soon as that blood is withdrawn and you get back to whatever your baseline level was in this study, you're reverting to baseline. That is weird shit, right there.

[Megan]

Isn't that weird shit? This was also done in healthy but untrained subjects. And there's a lot of blood volume games that happen almost immediately, especially in untrained athletes. And the cool part is that they isolated here that it was largely due to blood volume as opposed to like structural and functional changes in the heart. And it shows just how much of an impact that is has.

[David]

Yeah. And just how quick all this is. It's so, so strange. And so some other fun wrinkles here. It decreases at altitude, up to 6 to 9% decreases in one of the studies we saw, but it varies. But stroke volume also decreases at altitude. One of the reasons that countering blood volume loss is one of the ways to perform up high. And I think mastering that kind of explains my Leadville experiences.

[Megan]

I think that's where heat at altitude, actually sometimes it's funny because I have sat here sometimes as a skeptic of like, like, are heat and altitude too much stress? But when you think about it, actually, heat may be even more important at altitude to counter some of those blood volume. The natural blood volume changes that happen in altitude and that also persists at altitude, like, likely blood volume. Like, even if you adapt to altitude and are there for a longer period of time, that's not improving.

[David]

Yeah. So everyone's out there probably scrunching their foreheads like. But doesn't blood volume go up at altitude? It's like, no, actually plasma volume goes down, but your red blood cell numbers go up. So your hemoglobin mass goes up even while your plasma volume goes down. So that seem seems like a great adaptation because hematocrit percentage of red blood cells goes up, but we don't necessarily care about hematocrit number. We care about total number of red blood cells. And so if you increase the plasma volume number, yes, hematocrit might be going down slightly, but the overall number of red blood cells will have more room to increase, which also probably explains altitude responders versus non responders. Non responders might have iron limitations or other things, but sometimes it might just be a blood volume limitation where they don't have enough in the denominator like total plasma volume and to increase the red blood cells to adapt altitude. So for everybody out there that's thinking about altitude training, this is the one to emphasize, especially if you're coming from sea level, like heat is the gateway. And then as soon as you get to altitude, do heat, because it decreases almost instantly upon introduction of altitude, but

[Megan]

rises almost instantly upon introduction to heat. And so this actually leads me to one of my favorite studies, which is called the effect of sauna based heat acclimation on plasma volume and heart rate variability. And this took seven men and had them do a combination of different training days. So 17 days of baseline training and then 10 days of training plus sauna. So they added 30 minutes of sauna immediately after training.

[David]

And I cite this study all the time, so much that I know this percentage off the top of my head, which is. Drumroll, please. Perfect.

[Megan]

Also, I believe you put this. Did you say this on ritual?

[David]

Yes, I believe so.

[Megan]

Yeah. I was like, I remember this. I remember exactly where I was when I was walking. I was pregnant and listening to ritual. And you were like 17.8%. And I was like, yeah, bro, off the top of your head, bitches.

[David]

17.8%.

[Megan]

DJ, that.

[David]

So plasma volume increased of 17.8% after just four exposures. And this was in advanced athletes here. And so that was the number. I think this was a 2015 study. When I was starting coaching and really working into it, I saw this study and I was like, okay, that doesn't compute. It doesn't make sense. And if that is true, which other studies, maybe not such a high magnitude, but similar levels, right? Like you're seeing 10 to 15% increases in plasma volume almost instantly upon interruption of repeat. If that's true, this is the thing that everybody needs to be talking about all the time. What else in the human body changes almost instantly? And what we know from other studies is this will be a fitness signal. Yes, you might. In elite athletes, there's a million other things. It might be too small to isolate, but this should make training feel better, it should make you perform better, adapt better, and all that. So as soon as I heard 17.8%, I started shouting it from the rooftops. I would write about intro in our magazine all the time and post about it all the time, Cite this study so much that honestly, I'm kind of

[Megan]

chafing to put some squirrels nut butter on that study. Yeah.

[David]

And it's just like so obvious that this has to be a signal that matters because plasma volume is not just performance. Plasma volume also includes like healing factors and other things and is how you transport, you know, glucose in the body and you know, you get everything that the cat that you need to capillaries. So that to me was wild. One other wrinkle here is that blood volume variation can also be seasonal. So in wintertime people will go down naturally. That's likely connected to the heat signal. Can be by up to 15% in

[Megan]

some of the studies we saw, which is pretty substantial. But I feel like this whole conversation rests on kind of like optimal physiology and optimal response. And I feel like one of the big things that I think about as a coach is this involves, you know, having optimized iron levels, which is key. Like oftentimes I have athletes that, you know, have low iron. I'm like, let's be really careful with heat training because it kind of overrides stressors and can become very difficult.

[David]

Yeah, I mean we gotta stop there though, because iron level, that's the biggest point here. Because the plasma volume change will probably happen for any athlete. Like if you introduce heat, if you start training, just something that's in the background, like that will increase. But if you can't produce the red blood cells that go with it, you're getting like maybe a quarter of the benefit or maybe even less because you'll find yourself extremely iron depleted in your blood. Like your hematocrit will be to the floor.

[Megan]

In fact, it could be a negative stimulus because sweating is a way to lose iron stores. And so like excessive heat and excessive sweating can actually plummet your iron and thus plummet your red bl. Also it's, it's very tricky. Red blood cell production.

[David]

Yeah, but iron levels and iron intake, yes, you will always want you to get a blood test. Make sure you get just an iron panel. You can do this anywhere. You can do this at quest or athlete blood test or something. And, and they're not too expensive if you're just measuring that. But once you see that optimizing those numbers, pushing them pretty high can sometimes involve quite high doses, especially for female athletes. Like we'll always get messages from people that have a ferritin of like 34 and pretty low blood numbers. And their doctors will say, ah, don't worry about an iron supplement there. It's like, yes, do it. But even if they do say Worry about it. They might say, take a 25 milligram

[Megan]

supplement every other day. Yes.

[David]

And I'm like, eh, you know, you can ramp that up probably and don't want to give medical advice here, but we have a lot of our athletes taking 85 milligrams that are thinking about this because that often is a good number to find increased levels and sometimes even higher nowadays.

[Megan]

And the other thing to think about too is, is low energy availability. Some of the lowest hemoglobin numbers that I see are in athletes that are struggling with reds. And it becomes very tricky. And I think it's hard to say exactly which part of the equation that impacts. Um, I think it honestly just impacts everything. When we're thinking about blood volume, when we're thinking about red blood cell production, it just impacts all of those pathways. And so this also becomes tricky in that context too.

[David]

I'm set you up for a controversial take.

[Megan]

Oh, shoot.

[David]

I don't know if you want to do this.

[Megan]

I do. You know what? I'm grinning over here. I got endorphins. Bring it on.

[David]

Let's say we, we see an athlete number. No underlying health conditions, no bleeding conditions, anything like that. And it's an 11.2 hemoglobin level. How often in the cohort of athletes that are sending us blood tests, not the athletes who coach, just like on Patreon and things, how often do you think those athletes are under fueling versus having some genetic issue that prevents iron absorption?

[Megan]

Oh, my goodness. Are you gonna make me put an exact number on it?

[David]

Exact number.

[Megan]

86%.

[David]

What?

[Megan]

Whoa, whoa, whoa.

[David]

You're gonna make me edit. Edit the. Out of this podcast?

[Megan]

What do you think?

[David]

I think it's lower than that.

[Megan]

I mean, but when you think about it though, those things are rare. You know, it's. You're gonna say, what's, what's your guess?

[David]

Are we gonna go have to censor this number?

[Megan]

I'm just worried. I think. Leave it in. I mean, give me your number and then give me the explanation. 50, 50, 50. Okay. What's. What's the other 50% that's causing it?

[David]

The other 50% is. I don't want to edit the podcast.

[Megan]

You know, it's. I mean, it's. I think the population that we work with, like, you know, when you think about the baseline in runners, like 60% probably struggle with low energy availability. And so, like, that's a really high prevalence. And so when you think about 60% of people at baseline struggling with it, it's the Most likely explanation most of the time.

[David]

Yeah, I like it.

[Megan]

Maybe I'll lower it to 75%, but I'm not going that much lower.

[David]

And it's just like, let's do a little insert here. Do you just want to edit? Lower it to 30%? Just as 30%.

[Megan]

You're going to drop it that much?

[David]

I want to be controversial. I don't want you to get us canceled.

[Megan]

I don't. I'm gonna stand with no.

[David]

I mean, I love it, but also, it's challenging for people.

[Megan]

Well, it's also hard to. I think the challenging thing, too, is, like, low energy availability is a diagnosis of exclusion often. And so it's harder to prove. And so by saying 75%, it's almost a safe answer in some way.

[David]

Yeah. No, I mean, and I also think it's important to challenge people that might be, like, you know, on the edge. I started coaching a pro athlete recently, and it's been very hard to have this conversation with them. And then they started working with the top nutritionist, like, one of the top in the world. And the nutritionist identified the problem immediately with the same type of certainty that you have as soon as they talk to them. Um, and, you know, obvious it's harder for me to have that conversation because it's just tricky. Like, you want to be direct and open and loving, but sometimes it needs a little bit tougher love. And they were able to have that with them. So iron levels, energy availability. The other is hydration status. So if the driver here is liquid content in blood. Blood in. In blood volume, you want to have the liquid on board. So as you introduce these stimuli, Staying hydrated, good electrolytes. Quite key. Much like that study that was using a type of saline, like, that's. This is where electrolytes might come in handy as you're increasing blood volume, and

[Megan]

I think especially relevant at altitude, too. And this is an area where sometimes I'm just, like, bad at hydration. And honestly, reading the studies this morning, I'm gonna be like, it is a life priority. I'm gonna have a big bottle around at all times.

[David]

What did I do with the precision? 1000 tabs the other day? I was just, like, stuffing them into your bottle.

[Megan]

Yeah, just stacking them.

[David]

Introduced a little bit of heat for the first time in forever because we've been too scared with a heart. But now you have the medication on board. We have some assurances. Just a little bit. And you were drinking plain water. I was like, what are you doing?

[Megan]

He just came over with.

[David]

What are you doing?

[Megan]

Like, plunk, plunk, plunk.

[David]

Have you read these studies? I punk the crap out of those. And so if you're looking for an option, I am obsessed with precision. 1000 tabs, like the salt tabs.

[Megan]

Okay. They're actually delicious.

[David]

They're so tasty. How many have I drank over time? Probably so many that whatever disclaimers are relevant are important for them to put in. Because I if it. I don't know if they cause any problems, I'm going to get those problems.

[Megan]

Okay, here's the thing. This, I always say, here's the thing,

[David]

and then something, something funny, something that gets us canceled.

[Megan]

They're a little bit effervescent for me during training. You know what? I think I can get over it because they make me feel really good.

[David]

Well, we had a message from a listener that they do have sodium bicarbonate carbonate, too. It's one of the main small amount. Yeah, well, when you have as much as I do, it's not a very small amount. Right. Maybe I'm constantly loading a little bit of sodium bicarbonate.

[Megan]

Maybe you're over plunking it.

[David]

No, it's not over punking. It's the perfect amount of punking. Do not attack my punk. But something like Precision 1000 or other thing, like, yes, a lot of people say you just need water. And that is true if you have a salty diet. But for someone like Megan, that is blood volume limited to a major extent right now. It probably is helpful. And so what does this mean on a broader scale of putting it together? Basically, it means, one, train consistently. That's the most important thing. Um, two, heat is your friend. So this is especially true in periods of D training. Um, but it applies throughout all of the training process. Because what we're probably looking at here, if we're stacking percentages in a qualitative fashion, is you get maybe 10% from training, 10% increase in blood volume. That's really subject to going down. But then heat on top of that gives you another 10 or 20%. And that those numbers are subject to going down at all times. It's not like you're gonna keep increasing blood volume, but by keeping it at the top end of your physiological maximum most of the year, close to it, you're probably going to be so much more primed to perform, recover, adapt, and be healthy. Like, it'll decrease your resting heart rate, should improve your hrv. Um, and we've talked about all these studies recently where this can be accomplished versa through passive heat, um, things like sauna, hot tub. It can be accomplished by just wearing a light jacket. Sometimes on your runs, it really takes the lightest of stimuli.

[Megan]

And that's where year round heat training has a big impact too. Because if you think about that training better in this context of blood or blood blood volume and how you stack that across power output and raising the ceiling, and that really matters, especially as

[David]

it relates to stroke output and VO2. So all of the studies now are

[Megan]

finding that, dude, you do this all the time. I'm gonna call you out right now. You combined stroke volume and cardiac output in the same. You just mash them together. Sorry, they're having a fuck party over there. Don't do it.

[David]

Okay.

[Megan]

They're like, for some reason that like my brain is like, you're not a

[David]

fan of my shit strokes. Yeah, I get it, I get it. I hear you. I see you.

[Megan]

Your stroke output drives me nuts.

[David]

No, actually noted an important, important caveat there.

[Megan]

Sorry, I'm always a yes and, but I'm like, no. Boo.

[David]

But the studies on VO2max in particular show that increasing these variables directly improves VO2max. Nothing else improves VO2max for advanced athletes. Like it's the only thing. That's why it's so common. And the biggest like sub thesis there is not to overdo it, that it takes very little heat to get most of this stimulus. It could probably be one or two times per week. I like the rest days being a great time because your blood volume probably decreases on a single rest day. So adding heat on that day can make a huge difference, which can be

[Megan]

an argument against taking rest days. But if you add heat in, you're like, look at this perfect world situation.

[David]

Tapers. Another good time to do heat because that's when your blood volume might retract a little bit. Periods of detraining, like I'm gonna be going through here year as you're returning and then just generally to support your training year round. And then anything other than heat that we need to really be thinking about here. I think it's mostly just a heat signal.

[Megan]

Heat hydration. I think training is exciting, like, especially if you're coming off a period of D training. This can happen like rapidly. And it's kind of fun to see like those day over day gains. And that's probably a result of blood volume improving day over day.

[David]

Yeah. So this is maybe the most important easy, low hanging fruit that applies across all training theories. Like it doesn't matter what you're doing out There this probably matters. And so, yeah, figure out a way to make some of this happen. And it can be very, very small doses, probably 20 minutes once a week. That was the study I wanted to do to propose to end this is if we did maybe not 20 minutes, maybe 30 minutes once a week or

[Megan]

maybe 20 minutes twice a week.

[David]

Well, no, that's the thing. I want to see just how low the dose response goes that 30 minutes once a week on a rest day. How will that vary between a control group and an intervention group? In fact, any of our younger graduate students. Students out there listening, try this, because I bet that one stimulus will stack up across like five or six weeks to be a relatively substantial difference across two groups.

[Megan]

And I think, too, my brain also wants to go to the detraining portion of this is how much training can you hold on, like blood volume to. So if you do like two or three days a week of training and adding heat in there, can you maintain that? And so I'm curious about that as well.

[David]

Yeah. That this could be the way to train without training.

[Megan]

Yeah. Well, I mean, sometimes it's like, you know, you're in a busy period, you're trying to recover from something. Like, it's. It is helpful to think about this.

[David]

And a lot of our listeners aren't even runners. You know, they're. They're out there doing their thing, like a little bit and not doing that much aerobic training. This could be pretty substantial direct benefits. Um, and I think it's becoming more of a common place practice. There's a reason that our friends in Northern Europe are so into this stuff. Right. Like, they were on this.

[Megan]

The Norwegians were into the sauna way before any of these conversations.

[David]

Yeah, yeah. Did you see there was some song for the Euro? What is it? Whatever their pop music music competition, that was a song about the sauna.

[Megan]

Ooh.

[David]

And I think it was not Norway. I think it was like Finland or Sweden or something. But it's a really good song. It's catchy as hell.

[Megan]

Oh, we should. We should listen to it.

[David]

But it points out just how important this is culturally. And the. The reason is that it does make those people feel better in cold climates, most likely. So they're getting the seasonal benefit all the time. That will make them healthier long term. And I think it sometimes gets, you know, pushed to the side as a cultural thing. Whereas, in fact, I think it's a performance health signal that was identified very earlier and then became a cultural thing, much like a lot of the rules around food oriented around, like, that's actually a little too controversial.

[Megan]

I'm like, dude, where are you going with that?

[David]

Talking specifically about a lot of religious rules around food stem. Back to, like, if you look at the origin point, it was a public health thing. But that. That's a dad fact. That is not important.

[Megan]

You know what?

[David]

You know what I'm gonna do right now?

[Megan]

Are you gonna edit that, dad?

[David]

That was me slapping myself way too hard. No. Ouch.

[Megan]

I feel like you're gonna. You left a red mark on your cheek from that one.

[David]

This is the first time I've ever slapped myself on the podcast.

[Megan]

Yeah, you went hard, man. I don't. Don't understand that. You should be gentle. Okay, good. Away. Wake up.

[David]

All right, so let's get on to the news before we do that quick promo for Patreon. So much fun going down right there. Patreon.com swap swap. We have 193 bonus episodes.

[Megan]

We've been having so much fun in those. I was back this week. I took three weeks off of the Patreon. I've never done that. And it was so fun.

[David]

We had a riff on Moana that might have been the funniest thing we've ever done.

[Megan]

It was a continuing riff.

[David]

Yeah.

[Megan]

And continuing singing. You said on there. This is a. A lofty goal. You're like, if you plot me anywhere in Moana, I can tell you exactly what they're going to say next.

[David]

Yeah, well, people need to listen to that episode to get the rest of the details. We just do questions and answers there. So if you like the podcast, that's just $5 a month. But maybe most significantly, there are training plans for every distance. There are, like, hundreds of training articles now that are all organized into different cohorts. So if you're like, oh, I want to read about training theory, don't buy a book. Just go get our Patreon. So five or ten dollars a month, heart rate zones, all that good stuff. Let's read something from here.

[Megan]

Okay, but first, at what point do you think we're going to stop making training plans? Maybe never. They're just going to keep evolving.

[David]

And I think some of the.

[Megan]

Is it too many? You know, like when you go and look in your closet and you're like, this happens to me sometimes because I have a lot of old clothes from high school. And I'm like, but there's like, 20 shirts. How do I choose? Do you think we're ever going to face that problem?

[David]

If we have the cheesecake Factory menu problem.

[Megan]

Yes, exactly.

[David]

Okay. Yeah, yeah.

[Megan]

But, you know, the thing is, I actually love the Cheesecake Factory.

[David]

Yeah, Cheesecake Factory is great. And I think everybody loves the Cheesecake Factory. I think they prove the thesis that smaller menus are bad. Like, we went to a restaurant up in Nederland, Colorado. It's amazing. The kitchen at the Vault. Everyone go support them because they weren't doing great numbers when we were there, and we want them to.

[Megan]

Their burgers were incredible. I was like, how are more people not here right now?

[David]

Double Smashburger. Go for it.

[Megan]

Okay. Smashburger is my New Jersey jam. Give me a regular burger and a double Smash burger. And it's Double Smash burger every day of the week.

[David]

I'm just hearing you like the Smash,

[Megan]

unless it's stroke output, and I'm like, I'm out of here. Get me out of this room.

[David]

You just got the ick so bad.

[Megan]

I did, but they have a very

[David]

small menu at this place, which is my only downside. I'm like, you can just put a bunch of pages on there with random words and I'll be happier.

[Megan]

Just different iterations. I feel like you can iterate. They, like, brought us a Caesar salad with a crab cake by accident. And I was like, wow. Their Caesar salad comes with a crab cake. That's wild. But it just messed up.

[David]

Always looking for my small menu crab cakes in Colorado.

[Megan]

Yeah.

[David]

The mountains of Carter. You know, those mountain stream crabs are so popular.

[Megan]

I think you have a taste bias against seafood. I have never heard you say a single positive thing about seafood.

[David]

Well, I grew up on a river. Like a river. Like a river river.

[Megan]

And I feel like you have nostalgia for the river, but everything tastes like the river.

[David]

Well, yeah, I mean, some nostalgia, but.

[Megan]

Did you just drink the river a lot as a kid?

[David]

Okay. It was the type of river, the Chester River, America, Maryland, where it has the gloppy mud where you put your feet down and it goes two feet down.

[Megan]

Okay. I kind of like that.

[David]

Well, it feels good.

[Megan]

It feels really good in your feet. Yeah, yeah, yeah. It tastes gross.

[David]

Yeah. And then there were, like, clams and mussels and stuff in there, and you'd grab them and all of that. And then my dad would sometimes cook, like, catfish or whatever that we would catch.

[Megan]

Yeah.

[David]

And I gotta be honest, it was some of the worst culinary experiences of my life. I mean, to this day, even the slight hint of that makes me, like, kind of rock pulse.

[Megan]

Yeah. I mean, I don't know if catfish is a good seafood to start With.

[David]

Well, I'm sure catfish can be a delicacy.

[Megan]

I mean, I don't know, but the

[David]

catfish we caught, where we caught them, I don't know. Yeah, I think these catfish were listening to country music and doing some nasty things under the water.

[Megan]

They are probably more feline than fish, honestly.

[David]

Oh, my goodness. I'm just. But yeah. So our Patreon. Let's read something from that. I have a training plan success story for you. I just dropped a 4 minute 10 KPR coming off an 18 mile trail day with a big negative. So split. I'm on week 5 of the Champion 50k and 50 mile plan right now, and I'm feeling faster and healthier than I ever have. Thank you for giving such a valuable resource to the community. So that's the biggest advance in the last couple years, if you haven't seen it recently, is that we have champion plans now that have basically been vetted at the top international level with professional athletes that follow us there. It's very cool. Occasionally someone will message us on Patreon and I'm like, why am I not coaching this person? Why are they using a training plan?

[Megan]

It is kind of wild. It's like the most like a missed connection, a missed opportunity.

[David]

There's a 232 female marathoner on there using the advanced marathon plan. Like, you should probably get a coach. So. Patreon.com swaps3p all right, we're long way into the podcast already.

[Megan]

I knew I was like, we're gonna ball out on blood volume.

[David]

We feel it balled out so hard. Yeah, you wanted to smash real bad. So let's do some news. Let's start with the enhanced game. This was last night as a recording on Monday. And I'm skeptical about talking about this at all because it is so bad.

[Megan]

I don't want to give it coverage. It's like, I don't want to give it publicity. It is interesting though, and the things that we learn from it are interesting also. It is kind of fun that basically the enhanced athletes got dunked on in the a hundred meter dash. It was won by two non enhanced athletes and they were the only non enhanced athletes in the field. And I kind of love that.

[David]

Yeah, yeah, the hate games are dumb as hell. Um, basically. And the. The complicated thing here is we're gonna talk about satisfy Circle Pit in a moment and I have this.

[Megan]

Whoa, that is quite a.

[David]

Well, no, I have this big theory that it's not a personality to hate things that other people like. And that'll get to that point. But what I was thinking about the enhanced games is no one, like, likes it. The only people that, like, may partially respect it are trolls, people that are trying to prove a point, and the worst impulses of humanity, of Internet culture and all that. This is your worst Reddit troll brought to life. And the fact that this happened makes me so happy that it just resulted in a big wet fart.

[Megan]

It was a big, wet, slow fart. A slow fart, slow fart across the board. It was taking that fart a long time to run 100 meters.

[David]

Yeah. And I mean, it's just. It's frustrating. And the reason it's frustrating, frustrating is cultural normalization of, you know, doping. And this gets to a slight segue into the discussion that's been happening on running Internet about Cam Haynes. And so I don't want to make any broad pronouncements on this. You know, I know some people that really like Cam Haynes personally. He's, you know, supported us in just like after Leadville and stuff. And I don't want to get into things about him personally. But the controversy is that Sage Canaday reported him to usada, the US Anti Doping Agency, for talking, I think on podcasts about using, like, peptides or other performance enhancing drugs.

[Megan]

I think in an Instagram post as well, that admitted to it. And Cam has been open about this journey and he's somewhere in his late 50s, and so he's been thinking about this from like an injury perspective and, you know, a variety of health and lifestyle factors. But, yeah, I feel like at the end of the day, Cam has been competing in major marathons, including the Eugene Marathon, where he ran 2:30 something marathon, 239 marathon in meddled in his age group. And I think this does become a tricky, relevant discussion where the rules are the rules at the end of the day. And I think it becomes a slippery slope of admitting to doping and having that be some kind of okay thing within the community when it's clearly a rule that was violated.

[David]

Yeah. And the way that these are connected is cultural normalization that doping is cheating. And if we let it slide for any reason, reason, you're creating a world where cheating feels like it is the thing that other people are doing. And it feels like it becomes a prerequisite to compete. Which as we learn from the enhanced games, it's not the. Some people that are critics are saying, well, this just shows the best in the world are cheating. And it's like, no, actually.

[Megan]

Well, it shows the best in the World are probably very committed to their craft, like, you know, of showing up. And I imagine if you're, you know, at the point where you're competing in Enhanced Games, you get, like, one focus, you know, one. One event. And I imagine the, like, the discipline and the drive to train becomes a lot less.

[David]

Yeah. And just the. The frustrating part is that coaching some of the best athletes in the world now on, they are clean as hell.

[Megan]

Isn't that, like, a wonderful hug? It's so good to see athletes level up and to do, like, you know, you've coached athletes that are throwing down international performances that are 100 clean, and it's like, that is so cool to see.

[David]

But then you see Rachel and Tricken come out after Cocodona, who we don't coach or anything, but she was very open, saying that she can't be on the Internet because everybody's accusing her of doping. And the reason these people are accusing her, the dumbasses out there, is because they see things like the Enhanced Games or like, cam, and they're like, oh, well, that's what people do. And it's like, no, actually cheating is wrong. And. And it has to be out of the sport. And so the complication with CAM relative to the Enhanced Games is that, you know, aging athletes and other things, there are considerations there for how health that go beyond the, like, what the doping code is intended for.

[Megan]

But I think the hard part about that, though, is that if that becomes normalized in that age group, there's no way to compete at the top level. And it's like, that matters. Like, you know, when we're 55, 59, we're going to care a lot about age group podiums. I hope we're still competing then, and you don't want to have to be in a sport where, like, that's a prerequisite to competing.

[David]

I'm still going to be running on my messed up foot.

[Megan]

Yeah.

[David]

Every two weeks. That's kind of my trajectory here. But, you know, yes, I think that matters. And the distinction is that I can't, like, weigh in on the health impacts of various approaches to aging. Right. Like, that's not my area of expertise whatsoever. But there are rules in sports, and if you're going to be competing in sports, that is a privilege, and you need to follow the rules. And perhaps USADA will make a carve out in the future that allows people to compete, compete under these various circumstances.

[Megan]

Do you think? I think that could potentially be challenging, though.

[David]

Well, that's not our. That's not our role.

[Megan]

It's not our role. But if you think about that.

[David]

Yeah.

[Megan]

Do you think that would be a good thing for sport? A carve out that's like, you know,

[David]

well, the carve out wouldn't say it's okay to take like these illegal drugs. It would say, well, if you go through this process and check this box, you can do this race and maybe not be on a podium. Not to say you can do this and then compete because then it will become, become a, you know, enhanced games version for 60 plus year olds, which is not okay. So my point being there might be a carve out in the future, but until then, like, you can't compete if you're taking performance enhancing drugs. And there's a counter argument of like, oh, well, they don't get tested. And what I always say to people on Patreon is, look, treat your health first and then worry about everything else second, but respect the rules of this process because if we don't, you're creating a system that is going to incentivize everyone to cheat. Not just so it starts with older people or whatever, whatever the cohort is, or professional athletes in the enhanced games, but then it trickles down to 18 year olds who get this all secondhand and aren't listening to the swap podcast,

[Megan]

especially from like influencer culture and how it's talked about on the Internet.

[David]

Yeah, yeah, or whatever. Like, let's run where they accuse everyone of cheating. You know, like these terrible places that don't understand the real world. Right. Because if you talk to anyone in the real world, at least like in, in the US where we have these conversations, like it's not happening, happening anymore. And you know, when it was happening, everyone was whispering about it beneath the surface. So there is some precedent for that. So long story short, like, it's hard because I always want individuals to get maximum compassion and treat their health and all that. And I want everyone to compete and get the benefit of these incredible life experiences. But at the same time, you can't cheat. And you know, the cheating that is prevalent, it's for a bunch of reasons like, like, you know, Cam has said it was about healing or whatever. It's like, yeah, it's one of the reasons people do this stuff and it's one of the reasons it's banned and it has so many health concerns that go beyond this. So that was my big think piece.

[Megan]

Yeah, it's kind of a sad think piece when you think about it. It's like, you know, rules are rules, but at the end of the day I'm like, I'm so sad about this situation. You know, it's like I think aging

[David]

athletes need some sort of like treatment carve outs, not for performance enhancing drugs. Like, you know, there's a clear delineation maybe to be made between mean performance enhancing approaches that are really just designed to make 65 year olds jacked as hell, you know, versus things that are being done in medical standard of care. And I don't know where that line is, but.

[Megan]

And that's an evolving line. Yeah.

[David]

And maybe it involves not competing for, you know, podiums or whatever, but then it also creates a slippery soap. So it's a very difficult area and I have infinite compassionate to everybody out there there who might be facing this in their aging journey. But you know, there's also a therapeutic use exemption process where you know, some things can get that. So like that's a process.

[Megan]

But the hard part is like a recreational athlete is not going to get a tue. Like it takes a very high status of an athlete at a professional level to get it to ue. And so that becomes also a challenging process too.

[David]

Yeah. In conclusion. No. Satisfying conclusion.

[Megan]

Yeah. In conclusion.

[David]

Womp, womp. I didn't land that plane as well as I wanted to.

[Megan]

You landed it pretty well.

[David]

Yeah. And it's complicated.

[Megan]

I'm not afraid you're going to land it and like give so much compassion. There wasn't a failure.

[David]

No. Yeah, you gotta be like, if you don't have clean sport, you don't have sport.

[Megan]

Well, you have just like, you have so much compassion at heart that I was like, come on, show up strong.

[David]

I mean, it's complicated because in conclusion, I just edited out something I said that would be wrong. We love you all, everybody out there, like, even if you disagree with us. But I think the big point just to take home is that there is no sport without queen sport. And that is why.

[Megan]

Okay, that was well said. Oh, look at you. That's like a tagline on a T shirt.

[David]

Oh yeah. Oh, I just slapped myself again. But this one was in a sexy way. Actually, that wasn't sexy at all.

[Megan]

No, I was say. I don't know if I consider that to be sexy. Maybe I need to have a few more kinks in my life. But I'm like, no, I agree.

[David]

Okay, then. Satisfy Circle Pit. This was last week and I don't want to to beat a dead horse here.

[Megan]

Okay. My hot take on this is that I would actually love to run around a pump track for 20 minutes. That actually sounds like a genuinely fun, athletic event for our listeners that don't know, put it into heats.

[David]

Satisfy is like a luxury clothing brand. We've talked about them before, and they had a pump tracks, like up and down bike circle, essentially where people would be racing around for 20 minutes, but the whole time they were playing metal music, so live metal music and like, kind of like head banging and stuff in very expensive gear. And it got dunked on so much on the Internet. And I had a visceral reaction to this because, yes, it was a little cringe to see some of the videos, but everything is cringe.

[Megan]

And cringe is kind of cool in some. In many ways, it's like, be different. Like, express yourself. If that is cringe, and that is authentically, you go for it. Yeah.

[David]

And I'm just like, let people have fun.

[Megan]

Oh, running around a pump track genuinely looks fun. I think that they should allow body contact so that you can, like, deck someone off. You can deck your competition off.

[David]

Roller derby.

[Megan]

Well, I was thinking, like, you know how Nickelodeon, they had, like, you know, these, like, different obstacles and then slime time. We gotta get slime in some body contact in there and see what happens.

[David]

Legends of the Hidden Temple.

[Megan]

Yes. Yes. Oh, my God. Don't you think that's the perfect collab?

[David]

Our millennial listeners right now are all,

[Megan]

like, they're freaking the fuck out.

[David]

They're all going crazy. And our Gen Z listeners are lost.

[Megan]

What's Legends of the Hidden Temple? But that would be a better collab. Like, what was Adidas doing in there?

[David]

Yeah. All of our Gen z listeners, please, YouTube Legends of the Hidden Temple to know where our personalities came from. Yeah. So Adidas was collabing here.

[Megan]

I think that felt like a mistake on Adidas part.

[David]

Maybe. Why not? Why? I mean, it doesn't hurt Adidas's sales.

[Megan]

Yeah. But I just feel like, to go. It felt. It feels kind of different than their culture. Like, I think it's so cool that satisfy has this culture. Like, be different, be unique. But for Adidas.

[David]

So what I heard is be unique, be different. Sell $300 shirts.

[Megan]

Yeah, that's okay. That is the one tricky part that I have. But, but, but there's a place in sport for.

[David]

Well, the question is, would there be this same reaction if they were selling $20 shirts?

[Megan]

I don't think so.

[David]

You don't think so?

[Megan]

Do you think so?

[David]

You do? Yeah. I think the Internet just loves to make jokes at people's expense.

[Megan]

That's. That's Fair.

[David]

And, and, and I base that gets back to it is not a personality to hate things that people like. And a lot of people like Satisfy and now.

[Megan]

And a lot of people liked this event. If you were there, it seemed somewhat transformative and we don't need to shame them.

[David]

Satisfy isn't doing anything bad bad. Like, I understand a world in which people that, you know, drive Teslas feel the need to put a bumper sticker on there about, like, some terrible thing said by the CEO. Right. But as far as I know, satisfy is not the same situation. And so what are we doing? Like, just let people have fun and let people do their own thing. Like, no one is being coerced into buying a 300 shirt. It's something they enjoy and, you know, know that's life for you. Like, I don't know. I, I, I get great joy out of other people's joys. Like, that's where so many of the dad facts come from. It's just like me being like, look at this person that really likes this thing. I want to hear them talk about it. And that would probably go for Satisfy. Even though I'm not a clothing guy. Right. Like, I'm just not interested in, I don't care outside of functionality, why we like John Gianji rocks. But, you know, I, I don't know. I, I, it makes me feel a little gross to see some of the things that were happening last week on running social media.

[Megan]

Oh, the comments about had, actually. Okay, here's what I want to happen. I want you to throw down, get your foot healthy, and then throw down on the pump track. I actually think 20 minutes on the pump track would be your athletic jam. Put some bicarb on it. Take a gel out there. I like it.

[David]

You and me hold on to belief.

[Megan]

Yeah. I wonder how many people out there on the pump track had bicarb.

[David]

Yeah, dude, I. It kind of looks like a mosh pit, right?

[Megan]

Like, it did. Yeah. I mean, I imagine racing in that environment would actually be quite fun.

[David]

Yeah, that would be really great. They need to get Limp Bizkit out there next time. I bet Fred Durst is still out there making music. Get Limp Bizkit out there. They can make their play their new stuff.

[Megan]

Okay. If we told Limpitzkit that they're coming to Legends of the Hidden Temple, they might be there.

[David]

Dude, talk about a stiff biscuit at that point. Um. Oh, I hate myself.

[Megan]

No, I love you for that.

[David]

Okay, let's do some science snacks. We're pretty late in the podcast dude, we're not getting to any questions.

[Megan]

Let's just do lactate and then go to questions. I knew this was going to happen. The science was too good.

[David]

Okay, well as always, if you like question and answer, that's our Patreon episode every week where we really get down into it. So this is the topic that is interesting, is like really exciting in some ways and somewhat scary in others.

[Megan]

The science is so cool. To me, the practice of putting this into endurance sports gives me existential level of sadness.

[David]

I don't know why though. It shouldn't.

[Megan]

I just, I think when you start adding this it. When you think about the complications of like how this changes endurance sport and the fact that it could be such a performance enhancer, it kind of scares me.

[David]

Yeah, we haven't seen anything.

[Megan]

I don't want this to be like a pay for lactate playing field in.

[David]

We haven't seen any signal like that yet. You know, like it's out there enough as we're going to talk about in a second. So this is on lactate delivery called Molecular vehicles for therapeutic delivery of Lactate and exercise and medicine. It was by George Brooks, who is one of the most renowned names in endurance sports. And the fact that he's bringing this science to the masses in scientific journals is very, very relevant because he's seeing the trends probably. Um, but it's just new. It doesn't mean it's bad. Right.

[Megan]

I mean it's new versions of delivery to make this possible. And so like imagine if you made this readily available for athletes to just take every hour of an ultra and that fundamentally changes the game.

[David]

But what about taking every hour of a day?

[Megan]

Exactly. No, no, exactly.

[David]

That's the weird thing about this is.

[Megan]

And that's where. That's where it scares me. Yeah.

[David]

Delivery of exogenous lactate could have implications beyond enhancing training signal.

[Megan]

But also that's the part where I'm excited is I think it has a lot of implications for health and disease states including. We'll talk about ahead like traumatic brain injury. This could actually be like a really helpful therapeutic intervention for. And that makes me excited is what can we learn from physiology that we can take to helping people? And I draw the line of just like helping athletes run a little faster through something that you take every single hour.

[David]

I agree, I agree. So 3 points here. Lactate is a preferred energy substrate. So it's actually used as an energy source. That's why it's so relevant to talk about. And it's the predominant glucogenic precursor. And three, it's a signaling molecule. All of which raise your hackles if you're thinking about performance. Right. They are all extremely relevant.

[Megan]

And the signaling, to me, is some cool science. So it's both a myokine and an exorcine. So a myokine is something that's a signal that's released from the muscle, and an exor kind is a signal that's released during exercise from muscles and other organs. And so it has a lot of. It plays a lot of roles in things.

[David]

Yeah. So exogenous exercise. Yeah, exogenous exercise. I mean, it's not a one to one. I probably shouldn't be allowed to say that it's like stroke and cardiac, but that is basically what you're getting at here in some ways. So that is scary and exciting. But it's also why Megan is a little bit, like, hesitant here, but for the same reasons that it's weird for athletes who are healthy. You could see it being so helpful in hospitals or other settings. Settings with, like, athletes or. Or people who can't be active even.

[Megan]

Well, if you think about it. So lactate is a fuel source for the brain. And one of the big problems with traumatic brain injury is that you have, like, you know, the TBI induces like, kind of a blockade in, like, blood glucose uptake, metabolism. And so if you think about, like, providing lactate as an alternative fuel source, it could help those patients so much.

[David]

Yeah. And they're figuring out ways to transport it. That's the big revolution that's happening here. Here it's.

[Megan]

How do you get it to the mitochondria? Um, and so once it. Once it be. Once it gets to the mitochondria, it gets oxidized and used for energy as ATP. And if you figure out that process of how to. How to take it in exogenously and deliver it to the mitochondria, you can think about what happens.

[David]

Yeah. So we'll see where this goes. I mean, what the study was pointing out is that they're having breakthroughs in delivery now, and you could probably package this in a bunch of different sources. And so we're gonna keep our ear to the ground and keep you updated, because we don't know where this is going either.

[Megan]

Do you think it's in the pro peloton already, like cycling? I feel like it's the place where a lot of these interventions start. And we're seeing massive gains in the pro peloton, which we've speculated, like, you know, carbs Bicarb, Nomi, like, lots of different interventions happening, but do you think, like, any of this could be exogenous lactate?

[David]

We need to get messages. So, hey, if you're out there and you have access in the World Tour, send us a message about this.

[Megan]

And, hey, confidentially. Yeah, yeah.

[David]

Everything will be confident. Potential. Jim Cotton at Velo, the writer, he listens to the podcast. I know. Ask around and. And get those answers. I think it. If it's being used anywhere, it's there.

[Megan]

Yeah.

[David]

And if so, I'd love to hear about it. That. That being said, interestingly, we aren't seeing breakthrough power numbers like in the Giro d' Italia in any scary way. Maybe it's already been in the peloton for years, for all we know. You know, like, that's the complicated thing about professional cycling, is they'll be so far ahead that by the time something like bicarb becomes normal practice, every cyclist will be like, oh, yeah, man, I was doing that four years ago from unmarked containers.

[Megan]

I was getting some sodium bicarb at the grocery store.

[David]

Exactly.

[Megan]

It's the baking soda aisle.

[David]

Who knows where do you think it's gone?

[Megan]

I don't know. Do you think if you had access to it, would you take it?

[David]

No, no, not yet.

[Megan]

Yeah, and I think that's where I'm at too, is ethically, it feels a little bit weird until we have more data on it. Until. I mean, I feel like, until it's like, if it winds up being sold at the feed and we have. Have data on it about performance, that's where I could see it, like, impacting. But until then, this seems like a weird ethical decision to take before anyone else has access.

[David]

Well, I think we have a. Interesting reputation as early adopters, but we're actually not early adopters. We're kind of followers in some of the advanced techniques, but followers of the very best in the world. And so something like bicarb or whatever. Yeah. We're the first people to scream it from the rooftops. But we wait until. Until there's more evidence. Ketones were another good example. And, you know, Gnomeo a little bit behind, less so with that because of broccoli sprouts. And so the concern.

[Megan]

Because your bias of vegetables.

[David]

So the concern just becomes, like, the widespread availability of it and the cost.

[Megan]

I imagine this is gonna be very expensive, right? Maybe.

[David]

I mean, everything is right.

[Megan]

Yeah. Let's put this in the hands of Big Morton. It's gonna be like $40 a pop.

[David]

Yeah. So we'll see I. I think it's going to be a very interesting time because this does also theoretically apply to health and it might be one of those things that has health benefits.

[Megan]

I was gonna say, when you think from a longevity perspective and so many other, like, you know, I also question, like, cancer has a lot of lactate metabolism, and so my brain is going in so many different.

[David]

Oh, yeah. So it could go either way, even we don't know.

[Megan]

I mean, I think it would be beneficial, but you also don't wanna, like, feed a cancer either. So, you know, it's. My brain is going in many different directions.

[David]

Yeah. Who knows?

[Megan]

Yeah, who knows? Who knows?

[David]

But we're bringing it to you because my guess is this is a big topic of conversation over the coming few years on the podcast. And as always, we will tell you things as soon as we know them. So stay tuned to swap. And while you're here, click follow, give it five stars. We ask that once every six weeks or so, but please do. That helps other people find it. Um, and we just love you guys so much.

[Megan]

High five. I feel like you need to slap your fist in the face again for saying follow and subscribe.

[David]

I know. I always forget. Um, okay. Do you want to skip glucose and fructose or talk about it real quick?

[Megan]

Let's get to questions. We need to do at least one or two questions.

[David]

All right, now that was simple one, too.

[Megan]

The glucose and fructose is cool. Just get, you know, do multiple transporters in terms of your carb sources.

[David]

Okay. Before getting to question and answer, I do want to mention there was a study, another study on glucose and fructose that isn't the one we were going to talk about. That in the abstract said total cholesterol

[Megan]

oxidation with CHO in parentheses as the acronym. Oh, man.

[David]

If you guys out there ever make mistakes. I know I do all the time. Remember, we shouldn't say total cholesterol oxidation in your abstract.

[Megan]

But also, it happens.

[David]

It happens. Yeah.

[Megan]

Just I kind of wonder how that happened.

[David]

I mean, I think it's easy to just mess up words, though. It is kind of interesting how that happened. How did cholesterol get put in for carbohydrate?

[Megan]

Yeah, that's what I was wondering. I was like, are they using some kind of. I mean, I could actually even see the authors being right and then having some kind of weird computer translation in the. The publication process.

[David]

Yeah, I think the authors were from the uk. I think so. That's okay. Okay, let's get on the question answer first one here recently started watching cycling more and more to understand just how much of a freak the top cyclists are. I wanted to see if you could articulate the differences between the top athletes in their respective endurance sports. Take Connor Manson in the marathon, Christian Blumenfeld in triathlon, Tade Pagacha in cycling. Obviously, all of them work extremely hard. Is it their unique physiology that makes them great at their sport? Could Tade dominate the marathon if he went all. Could you crown one of them the king of endurance? And what would Connor Mance learn from today and vice versa?

[Megan]

I like this question. I kind of want to start with the king of endurance first.

[David]

Yeah.

[Megan]

Out of this list, I think it's Tade, his dominance compared. I mean, obviously, these are all dominant, incredible athletes, but I feel like Tade's dominance is at a whole other level.

[David]

Yeah, but if we're talking king of endurance, you got to go to the Kristen Blumenthal, like, the person that does the multiple sports, Right?

[Megan]

True. Yeah.

[David]

And Christian Blumenthal's been measured with, like, the highest VO2 max ever, and he's

[Megan]

dominant in the same. Maybe I just don't follow triathlon in quite the same way that I'm.

[David]

No, he's not dominant like Tate.

[Megan]

Yeah. But I feel Tom Tade's dominance shows if freakish endurance in a way that, like, is hard to argue with.

[David]

Yeah. And cycling, I think, will usually be the place that you find the, you know, king or queen of endurance, because there's a bigger funnel, at least in men's cycling. In women's cycling, it's a little bit of a smaller funnel, so that could be more complicated. It's probably running for women.

[Megan]

Also. I feel like, biomechanically, like, triathlon is limited a lot by, you know, how good of a swimmer you are. A lot of that depends on if you Swam at age 8 versus if you didn't. And so.

[David]

Yeah, that's true.

[Megan]

Also. It's a lot of. It is access, too, you know, and, like, you know, I feel like access funnels a lot of athletes out of that sport compared to cycling.

[David]

Yeah, and cycling. Everybody's riding a bike when they're young, and the people that start doing it a little bit, seriously, the ones that are good will be identified. And so you're really seeing the best of the best in the world in that sport in a way that you might not be seeing in running. Like, you know, a lot of the best runners might be channeled in other directions. So I.

[Megan]

Do you agree with me now?

[David]

I think I might go Tat A for men's. Men's king.

[Megan]

Oh, high five.

[David]

And on the women's side. Yeah, I'd probably go with a runner. Um, just because, I don't know, I'm not really good at answering this question very well. Kind of disappointed in myself. All right, next one on running versus biking. Um, okay, a question you've probably answered before, but what do you think is the hardest to be good at running or biking, coming from a lifelong runner who has never biked on roads?

[Megan]

Well, I feel like this built on the last one as to why it would be really hard for Totty to come into a marathon. I think running takes such a long term build of the body adapting to the mileage, like preventing injuries in that process, like the biomechanical efficiency and build that. I think running is a lot harder to excel.

[David]

Yeah, I think the injury part of running makes it just so much harder. And biking, you don't have to worry about that so much. So you can become a Watts monster if you have the physiology for it.

[Megan]

And we see that like, you know, Zwift does these programs where they identify riders riding inside and then take them outside and teach them, like, the skills to descend down a road. And that part is tricky.

[David]

Yeah, that part is tricky.

[Megan]

You know, every time that we've done, tried to do a fast descent, I'm like, whoa, that puts some hair on your chest.

[David]

There are injuries in cycling. It is, David. Being launched off the side of the

[Megan]

road, launching off a cliff is a massive cycling injury. Uh, but I think that's actually somewhat easier to teach than like, the long term biomechanical process of running.

[David]

Yeah, maybe. Honestly, I think everything at the top level is just immensely difficult.

[Megan]

Well, I think when you think about the bike handling of like, the true, like, you know, like some of the best bike handlers, it's like that takes years and years and years. But I think you can be strong enough if you have good enough watts to become proficient in the peloton and, like, have breakaway wins.

[David]

Yeah, yeah. As soon as you get any perspective on what the very best in the world at anything do, you get very, very intimidated by it very quickly.

[Megan]

Actually, watching some of the cycling videos, you just see them like, they're just like, hop up on a sidewalk, like, so easily on a road bike. And I'm just like, good Lord.

[David]

Or just randos on these YouTube videos that do crits in America putting out 101,000 watts or more around turns, and

[Megan]

you're like, what's happening?

[David]

Oh, my God. I've never put out 1,000 watts once. And, like, I'm pretty good cyclist.

[Megan]

You're a small boy.

[David]

I'm not that small. A lot of these people are really small.

[Megan]

You're a small boy. Aside from your blood volume.

[David]

Yeah. I don't know. It's. It's very interesting. And that doesn't just go for running or biking. I think it's a warm hug for just about everything. If you saw the best parent in the world, it'd be the same as those watts numbers that when you see TADE Putting out 400 watts at, like, zone two, essentially you just be, oh, my God. Well, I'm never going to compete with that. It's like, nah, just be okay. Being proficient and similar with running. Like, you try to be the best version of yourself. You're not trying to be the very best in the world. As soon as you try to do that, all sports become a mental mind fuck. Like, landmine zone. It's just really hard.

[Megan]

Oh, and it's kind of wild to think about the years of dedication and, you know, as you think about, like, starting something anew, it's like, whoa.

[David]

Yeah. Okay, next question. On uphill Tremo, I was just listening to the triathlon hour podcast and Christian Blumenfeld, he's in every one of these, mentioned using uphill treadmill threshold sessions a ton in his training as a part of lower impact. For that work, he said he also uses a similar format, like 5 by 10 minutes, which I've heard you speak of a ton of on the swap pod. Just thought it'd be cool for you and Megan about this and maybe even talk about it on this Tuesday's podcast.

[Megan]

We love uphill treadmill. It's actually wild. So I read this question. We were going to do this the other week on the podcast, and I read it and I got so sad when I was in the middle of my heart stuff because I was like, I just love 5 by 10. What if I can never do that again? All I want to do is just. That's actually amazing experience pain in the pain cave. And now it's like, I get to have that back. Five by ten is coming back to a pain cave near us.

[David]

Which really sad me is that my big setback was last Sunday. So eight days ago, and I just did a jog on the uphill treadmill because I was thinking, if I can do uphill treadmill, I can do anything.

[Megan]

And you were so excited after.

[David]

I was so excited because this is the path, right? If I can Just do that. This offloading thing, I'm good. And I had the biggest setback ever the next day. And now, you know, I'm really going to have to shut down and be careful to avoid rupturing this thing. And that's why I was heartbroken. Uphill treadmill is the. The gateway. It is incredible. And so the threshold work is like, so, so good for this. And doing these types of sessions that we've written and talked about before is the easiest way to progress. And so on Patreon, actually, there's something called the long term base building plan, which is designed to be an indefinite plan. You can do it 12 weeks or 6 weeks or 47 weeks. And it uses uphill treadmill workouts in addition to raising volume. So it's designed to be used long term. I think it is the way to most directly address the aerobic system that we have, like, in all of running. And the fact that he's using it now makes me a little bit sad because other athletes are going to be using it too. The ones that didn't listen to us are now going to listen to him, and we're going to lose some of our coaching advantage.

[Megan]

Oh, that's true. He's probably got a big pool within the world of, like, exercise physiology and how athletes relate to that. And so our five by ten is going to be more universal. Actually, we do six by ten. No, you work up to that, you build up to that. And that's the thing too, is like, that is uphill trick, treadmill specific. Like, we would never. I actually had an athlete once that saw six by 10. I was like, I didn't have treadmill access, so I did it outside. And I was like, no, don't do that.

[David]

That's the magic thing about it.

[Megan]

That's the magic thing is the mechanical breakdown is like, you know, you get the aerobic stimulus without having the mechanical breakdown and the risk. And so, like, you know, these sessions are great.

[David]

Oh, you're gonna be back to it so soon.

[Megan]

I know. I feel that I'm believing in it. Two and a half weeks might be a little soon.

[David]

Maybe two and a half months. I'm holding onto the belief for you, Megan.

[Megan]

I really. You've done such a great job in this process of, like, I don't know, I think, like, emotionally you've seen me so deep in, like, the grief periods and the really hard parts, but then also been the person that I've held the belief, and that's a hard balance to walk. And you've done it.

[David]

Yeah. I'm just so, so proud of you.

[Megan]

How'd you do it?

[David]

How'd I do it?

[Megan]

Yeah.

[David]

How'd I do it?

[Megan]

Yeah. You're like, this is complicated.

[David]

So there's this new thing called exogenous

[Megan]

lactate, so I got to spend munching on that.

[David]

I asked my mentor, Cam Haynes. You make it easy, right? I've seen you go through so much, and, yes, I heard what those doctors said. But I also know you're special. Right. And it was an honor to go through this part of the process with you. And I know it's just the start of something more. Like, I know you're going back to the best things. When we were in the hospital, I took videos of you for B roll for the eventual documentary.

[Megan]

That's belief. Actually, there was a hospital board that had, like, all the stats of the day. I was like, today's Tuesday. She gets this medication. And then I just wrote level 2330 on there because I was like, I want to believe while I'm in here. But you know what? We might have to. That might be sooner.

[David]

Accelerate it.

[Megan]

We might have to accelerate that one. But I did get strangely emotional. Like, it was. I've never, like, actually never injected myself with anything before. But as I was sitting there injecting that needle and, like, trying to stabilize and push it in at the same time, I actually got really emotional thinking about, like, what this new medication, you know, who knows what happens? And I'm super nauseous right now from it, but, you know, also thinking that this could be a new path forward, a new heart era for me. Yeah.

[David]

New hard air, reflecting on the journey. It's just wild. It's unthinkable that we're here right now. When you went down for your cardiac mri, I walked out of the room and went to the chapel. Like, every hospital has something like this.

[Megan]

And you walked inside and you slapped your face silly. Like, this is how I feel about religion.

[David]

No, I love religion.

[Megan]

No, we both love religion. I just grew up in a Catholic church.

[David]

Oh, yeah, you went to Catholic school, which my dad did, too.

[Megan]

I just went to Catholic school on Sundays, which only lasted for a few weeks.

[David]

Yeah, it wasn't for you. No. I mean, I love faith based systems, and it shows that. When our backs were truly against the wall, I went to the chapel. Right. And I'm gonna get my phone to see what I wrote.

[Megan]

Yeah, you wrote it. And my favorite thing was you wrote this thing in the chapel, but you also drew a stick Figure family.

[David]

Is it okay to read this? You think it's not like a wish that if you tell someone, oh, no,

[Megan]

no, you're not blowing out birthday candles then telling me what you wish for. But you drew the stick figure family of us too. And I saw that and you actually pulled this up the other day and it made me cry.

[David]

Well, this is the first one I brought up.

[Megan]

There's this church up outside of Jamestown and they have, you know like the church signs that say inspirational things. You edit them almost every time and send them to me.

[David]

It's just a mega edit.

[Megan]

Yeah.

[David]

But now the whole pile podcast. So it says, well, the original sign said do not quarrel instead be kind to everyone.

[Megan]

Actually, so many of the things I'm like, I agree. I co sign with that. There's so many beautiful sayings on those that I'm like, I should really think about a focus religion.

[David]

Oh. I mean, Jesus's teachings are so beautiful and so true, I think in the bigger scheme of things. But I changed it to do not quarrel instead. Shitpost everyone. So that's a little sacrilegious. Oops. But I hope everyone can see that I do feel pretty strongly about this. All right then. A lot of my Instagram reels that no one will ever see before.

[Megan]

You make a lot of Instagram reels for me.

[David]

I do.

[Megan]

They're great. They're beautiful.

[David]

How I spend my life. Okay. Megan, I love you to the moon and back. You carry my heart and no matter what, I pledge to carry yours.

[Megan]

Oh, now that's beautiful. I mean, a stick figure family of us. Yeah.

[David]

So I just love you and I'm so proud of you. And now let's go on to the

[Megan]

John G. Yeah, that's the most sentimental we've been into@john janji.com swap j a

[David]

n j I.com swap so much great stuff there.

[Megan]

Megan.

[David]

Are you done crying yet?

[Megan]

Oh, yeah, I'm here. I'm back to the archive sale. John G has an archive sale and it's actually really cool. You can go find like they have some cool pattern, like a lot of cool patterns and artists they work with and you can go get some of that stuff now with big discounts. Also they have a RD line that's a race line and the women's short and the men's short has a built in belt to it and so I can carry. I've carried like 10 gels.

[David]

Are those out now?

[Megan]

They're out now.

[David]

Okay. Go get the shorts.

[Megan]

The shorts are incredible. Yes.

[David]

I love Them. So, like, if you're carrying your phone, your gels, all of that.

[Megan]

I do know they have limited inventory, so if you want them, you would literally have to go get them now.

[David]

Hopefully they're not sold out by the time the podcast comes out.

[Megan]

Yeah, hopefully not.

[David]

You said the RD line, the shorts, and hopefully they're available. But if not, some other great stuff there. John G. Rocks. They didn't do a circle pit, but maybe I can convince them. Oh, this is the thing. This is what John G. Needs to do. Very similar design, so some sort of pump tracker, maybe just a circle.

[Megan]

And they need Nickelodeon slime.

[David]

Nickelodeon slime would be great.

[Megan]

Yeah.

[David]

But instead of metal music, it's all

[Megan]

like Vanessa Carlton, just Noah Khan out there.

[David]

No, no, no, no, no, no, no, no, no, no. I want this to be like bubblegum pop of the early 2000s.

[Megan]

I love it. You've been saying recently, you're like, I love it. How do you do it?

[David]

I don't know.

[Megan]

That was an A good. Yeah, that was.

[David]

I hit me baby one more time. That's how we get out of everything

[Megan]

from now on, whenever we need to. Literally, what you're doing when you're slapping your face.

[David]

Okay, a bunch of great listener corners,

[Megan]

but can I read? I put this one in there. Can I read listener corner today?

[David]

Okay, go for it.

[Megan]

You have to. Popcorn, Megan.

[David]

Popcorn, Megan.

[Megan]

Okay, this is a David appreciation message. And I know right now, like, you know, you're in a boot, and I think it's really hard to be in the place that you've been. It's been a long time. It's been since javelina, and the up and down journey of that is hard. Okay, so here's the David appreciation message. Megan, if you're reading this first, please hide this from David and try to surprise him with it at some point. I feel like this is a good point now. I'm currently up in L doing an altitude training weekend. Yesterday I did Hope Pass via Willis Gulch, and today I did Mosquito Pass. I was already in awe of the performances David was able to complete during the level 100. However, putting context to them makes his achievements astronomically more impressive. The burning hypoxic lack of activation from both of my calves at the beginning of Hope Pastoral clued me into just how powerful David is when he. He runs. He was able to run the entirety of Hope Pass, except for drinking from the stream, which I fully understand now. Like, what? How is that humanly possible? I am really writing this because I need David to know that he's a fucking inspiration. His performances at Leadville are. Are actively rewriting what is humanly possible. I do not think high carb is the only factor that got him there. David is such a special runner and a special human. I hope one day I can see him on the trails for that split second so I can tell him that he is awesome. Maybe even during the level 100 SP someday. Thank you both for all that you do. You fill me with such joy and knowledge watching you both chase your dreams and the science powering it all. Hope Pass is such, such a special place. Ollie, our little guy, 17 months now is Ollie. Hope after Hope Pass and just all the history, David, that you've had there. And I hope you're proud of that and I hope you channel that into some good belief.

[David]

Yeah, yeah, I gotta.

[Megan]

That's like all within you.

[David]

I realized last week that this was going to be a longer term thing and that I need to think about this as a red shirt year. And part of that self imposed and part of it's just the nature of being an athlete. And you know, I did everything like within bounds of right, but also not right at the same time, you know, and the tricky part for me now is that there's the line that like, you did everything right and things turned out wrong. Like, that's why I always said to you with your heart, right? And sometimes you do everything wrong and things turn out wrong. And that's kind of what I did with my foot, you know, but like,

[Megan]

you've done this stuff before and it's been okay.

[David]

And I was like doing within reasonable bounds. And the realization I had last week is like, all right, this is a much longer term thing now. And you need to accept that this is about getting back healthy next year and not needing surgery for it, which is still not out of the question. And in that context, I went back to a scene in the Leadville documentary. So nothing to lose. If you haven't seen it, I think director Cody just created something pretty magical with that. Not about. I mean, I hate things with myself, but just the way he told the story so authentic, authentically. And as I'm running toward the start of Hope pass at mile 37, I just say, you know, hope, this is why we're here. And it says that we named Ollie Hope Roach for that pass. And so that's it, right? It's hope. As you went through the hard things, I saw that. And no matter what was waiting on the other end, we'd have hope for that.

[Megan]

And I think you just recommit to that again and again and again. And light sometimes gives you a shit stew. And you're like, oh my God, this shit stew. I'm gonna believe in the best possible version of this stew that I can. And I think you've taught me. You know, I don't think my brain is baseline wired for that. But you spend enough time around you and you're like, oh, this is a much better way to live life.

[David]

Yeah. And try to be realistic, but at the same time, hope, hope, hope, hope. And then die. Like, that is such a beautiful way to live. And I think it's really the most authentic way to live. If you think about why there's existence at all to make this, broaden this out to like faith based systems even. Whatever it is, whatever the rationale is, it is a absolute fucking miracle. Whether it's a miracle of chemistry or a miracle of spirituality and a miracle of shitposting. And you know that celebrating that miracle and honoring that miracle by giving the same hope that created all of this in the first place, I think that's part of the goal. And I think being an athlete is beautiful for that because it's just an act of radical hope every day, especially with age. So that's my dream. And I mean, there's one more important, important point that I really need to mention.

[Megan]

I got the free laugh. This better be as good as I

[David]

think it's going to, baby.

[Megan]

One more time.

[David]

Boom. Hit myself again.

[Megan]

Perfect. That is radical hope right there.

[David]

We love you all. Hamzah.