Some Work, All Play – Episode 306: How the GOAT Fuels, Single v. Double Workouts, Heat and Altitude Study, Caffeine Genotypes, and Building Bone Density!

Hosts: David Roche and Megan Roche
Date: April 14, 2026

Episode Overview

This episode is classic SWAP: the Roches bring deep science, wild enthusiasm, and lots of humor to a packed agenda of running science, training, fueling, and life. Topics include: shoe hacks-gone-wrong, Megan’s breakthrough in bone density, cutting-edge studies on fueling, heat and altitude adaptation, double workouts, caffeine genetics, and a thorough look at super shoes. As always, they flavor it all with playful banter and love—for each other, athletes, and science. This summary highlights key segments, practical takeaways, and memorable quotes as you journey through podcast #306.

Table of Contents

• Shoe Experiments & Fails – 00:04–04:30
• Bone Density—Megan’s Breakthrough – 07:20–15:02
• Boston Marathon Plans & Weather Obsessions – 15:02–16:33
• Fueling: The GOAT, Tae Pagacha, and Carb Insights – 21:07–31:54
• Heat + Altitude Science – 32:15–41:51
• Single vs. Double Workout Study – 46:40–52:47
• Caffeine Genotype Study – 52:53–62:47
• Super Shoes and Injury Risk – 67:03–70:19
• Listener Q&A Highlights – 70:51–85:00
• Listener Corner: Showing Up & Self-Compassion – 87:07–End

Shoe Experiments & Fails (00:04–04:30)

David’s DIY Attempts

• David tests out the new Adidas Agravic Speed Ultra 2, finds it heavier than its predecessor.
• Extreme solution: “I took this knife and just chopped off some unnecessary lugs…” (01:13)
• Loads of shoe slicing and even lacing hacks, resulting in a lighter shoe but a compromised sole—full shoe deconstruction led to a blown-out outsole on Green Mountain.

Quote:
“I got the weight down. But at what cost?” – David (03:22)

Reflection:

• Running shoe performance is personal, but DIY hacks might structurally damage shoes.
• Ultimately settles on the HOKA Rocket X Trail, accepting toe damage in exchange for weight savings.

Bone Density—Megan’s Breakthrough (07:20–15:02)

Megan’s Health History:

• History of long-term prednisone for autoimmune issues seriously reduced her bone density.
• Despite consistently normal periods, her DEXA scans previously showed low spine density.

The Big Reveal:

• Megan improved her spinal bone density by 1.1 SD in one year with targeted nutrition, recovery, and non-traditional strength work.

Practical Insights on Building Bone

• High-carb fueling, especially on runs over 60 minutes.
• Focused on daily recovery fueling (Science in Sport Beta Recovery, real food like burgers, etc.).
• Thorne supplements (Advanced Bone Builder, Vitamin D, calcium).
• Consistent cross-training, child-lifting (“he’s a heavy kettlebell!” (11:14)), and daily-life “weight vest walks.”
• Limited traditional plyometrics/strength due to inflammation—key message: diverse ways to load bones work.

Quotes:

• “Whatever number you have is not your destiny.” – David (09:09)
• “It was so exciting...now when I do strides, I’m like, these are my plyometrics.” – Megan (13:32)

Boston Marathon Plans & Weather Obsessions (15:02–16:33)

• The Roches are heading to Boston—excited for a “date weekend.”
• David obsesses over weather patterns: “It looks like a tailwind...it’s gonna be spicy!” (15:22)
• Shout-outs for runners Jess McLean and Amanda Vestry.
• Megan’s logistical concerns: “How are we going to get around the course? Have we thought about that yet?” (15:49)
• E-bike debate: more insurance money jokes, less parental safety.

Fueling: The GOAT, Tae Pagacha, and Carb Insights (21:07–31:54)

Ultra-Endurance Fueling by the Numbers:

• Discussing Enervit’s profile of Tadej Pogačar (pro cyclist) and his staggering fueling plan:
  • Breakfast (3 hr pre-race): 250g carbs, 40g protein, 30g fat
  • Pre-race: 60g carbs, 5g protein, 3g fat
  • During: 130g carbs/hour with minimal protein/fat
  • Post-race: 120g protein
  • Total for the day: ~7,400 kcal, 1,500g carbs

Runner Takeaways:

• Carbs are king—even the highest-level female cyclists now hitting >100g/hour during.
• Runners typically eat less pre-race, but hosts highlight missed performance opportunities.
• High carb fueling is gaining traction, but skepticism remains—especially in trail/ultra communities.
• Female runners notably under-fuel compared to their metabolic needs.

Quotes:

• “The fueling isn’t just within the race... you kinda just need to keep the fire burning.” – David (25:14)
• “The idea being that...if you looked at your fitness in a snapshot in time...the same applies with fuel.” – David (27:35)

Funniest Moment:

• Carb fueling as “the mullet of nutrition: business on the top, party on the back.” (22:54)

Heat + Altitude Science (32:15–41:51)

Breakthrough Study Review:

• New research overturns old wisdom that heat training “cancels out” altitude adaptation.
• Study: 46 elite skiers/biathletes at 6,000 ft. Three groups: (1) altitude + heat suit workouts, (2) altitude only, (3) sea level.
  • Result: Heat+altitude group saw nearly 3% hemoglobin mass gain, while altitude-only <1.5%; sea level, none.

Implications:

• Combining passive heat (e.g., “heat snacks” in saunas/tubs) with altitude = more red blood cells, potentially better performance.
• Iron supplementation is crucial alongside these interventions (all altitude groups received iron).

Quotes:

• “Heat, you throw it on in almost any circumstance and it does this change…” – David (39:09)
• “It’s just relaxing for the most part...you don’t need to kill yourself.” – David (38:20)

Memorable Moment:

• Megan’s perfect recovery formula: “Pizza with ranch dressing and a bath... that’s all the foreplay you need.” (41:51)

Single vs. Double Workout Study (46:40–52:47)

Study in a Nutshell:

• Compared 1 x 60 min threshold (6x10min uphill) vs 2 x 30 min threshold (2x3x10min, 6h apart)
• All athletes fueled with 70g carbs/hr

Results & Coaching Take:

• Single sessions: More acute fatigue, higher perceived effort (“drift” in HR/lactate); doubles: less next-day fatigue, better for high-volume athletes.
• For most, occasional “drifty” workouts (single, big session) are beneficial—a big stimulus is good if you’re not going for mega-volume.

Quotes:

• “The drift is actually a good physiological signal rather than a bad one.” – Megan (49:41)
• “If you’re only doing one or two workouts [a week], you might want the bigger stimulus…” – David (49:28)

Caffeine Genotype Study (52:53–62:47)

Key Study:

• 94 athletes, analyzed the CYP1A2 gene (AA = fast metabolizer, AC = intermediate, CC = slow).
• All groups, even slow metabolizers, got performance benefits from caffeine—though to varying degrees.
  • Fast: 4–12% improved lift velocity
  • Intermediate: 3–9%
  • Slow: up to 4%

Practical Tips:

• If caffeine upsets your system, you may be CC (slow). Gentler doses (e.g., Megan’s 25mg gels) are safer.
• Most people are intermediate or fast and can try 100mg/2hrs strategy in long races (with caution).

Quotes:

• “Caffeine basically helps everybody. It’s just a matter of how much.” – David (53:14)
• “For a lot of studies...I’ve had this vibe that slow metabolizers, caffeine has an ergolytic effect....but here it is, it’s ergogenic!” – Megan (57:36)

Super Shoes and Injury Risk (67:03–70:19)

Study Summary:

• Compared Nike Vaporfly (super shoe), Invincible (cushion shoe), Brooks Levitate (traditional) in 30 runners.
• Vaporfly improved running economy, no increase in biomechanical injury risk factors.
• Invincible had lower “load rate” (impact stress) than others.
• Myth-busting: Super shoes are NOT inherently riskier; running faster due to these shoes may increase load instead.

Quotes:

• “People are like, 'Oh, you’re going to get injured.' The more we see on this, the more...the shoe that doesn’t protect you might be higher load rate.” – David (68:50)
• “It’s shoes... it’s not science, it’s fashion.” – Megan (69:08)

Listener Q&A Highlights (70:51–85:00)

On Sleep and Training Adjustments

• Emphasis on not panicking over poor sleep—consistency trumps perfection.
• Most athletes can maintain training even on interrupted sleep, unless chronic/debilitating.
• Practical sleep tips: early bedtime, bedtime routine, adaptable sleep aids (Dream Shot, Sleep Elite).

Quote:
“Taking the pressure off is the first step...Being relaxed, that counts as sleep.” – David (71:57)

On Video Games & Cross Training

• Listener tip: Use aero bars and a game controller to play video games on long indoor bike rides.
• David’s classic: “Perfect Dark” as his video game of choice.

Miscellaneous Fun

• Megan’s bra talk—a John G. long bra and race bra changed listeners’ running lives.
• Megan grew up playing Crash Bandicoot; David champions Perfect Dark and N64 nostalgia.

Listener Corner: Showing Up & Self-Compassion (87:07–End)

Listener Letter:

• A runner shares how meeting the Roches at Western States motivated them to start—and finish!—their first 50-miler (top 25%).
• Letter highlights the healing power of community, permission to fail, and showing up.

Quotes:

• “If you do this, what else can you do in life?” – David (91:03)
• “What happens if you give yourself permission to fail and to take a chance...A lot of cool things happen.” – Megan (89:02)

Personal Updates:

• David announces he won’t run Canyons 100K (thus, no Western States this year), taking care and self-compassion over grind-at-all-costs.
• Reflection on moving through disappointment: “You need a period of grieving for that goal.”

Memorable Moments

• Shoe hacking: David slicing lugs off a new trail shoe, only to destroy the sole. (01:13–03:17)
• Bone density gains against medical odds, and Megan’s joyful “bone gains” celebrations (07:20–13:32)
• Carb math: The hosts break down insane fueling numbers for the world’s best cyclists (21:07–25:31)
• Banter peak: “Pizza with ranch in the bath...that’s all the foreplay you need.” (41:51)
• Witty self-ownership: Megan “roasting” David; “I’m a humor bottom.” (70:41–70:43)
• Classic listener impact: SWAP community literally changing lives and finishing huge goals.

Key Takeaways

• There’s no single way to build bone density: Fueling, varied loading, and self-knowledge matter most.
• Carbohydrates power performance—don’t be afraid to fuel big, especially if cycling and racing long.
• Heat training + altitude is a winning combo (with iron!), overturning outdated beliefs.
• Listen to your body for sleep and recovery, but don’t stress over perfection.
• Even “slow” caffeine metabolizers benefit, but dose accordingly.
• Super shoes don’t cause more injuries—running faster does.
• Most of all: Show up, try the hard things, and don’t judge yourself for the outcome.

As always: “We love you all!” – David & Megan