A (0:00)

If you are loving what you're learning in the podcast and you want to start applying it to your fitness routine, you can try one of our free classes. No credit card required, just drop your email to get access. This is a Upper Body Build class taught by myself. To take the class, visit portal.evlofitness.com I'm Dr. Shannon Richie. I'm a doctor of physical therapy, fitness trainer and founder of Evil Fitness. In the Dr. Shannon show, you'll learn applicable tools to improve your health based on science. Welcome to the show. Hi everyone. I am so excited to be back behind the mic today updating you on some science. In case you didn't know, I took a little break from the podcast. I had another baby in August and my two kids are 16 months apart. And quite honestly, this podcast is a lot of work. I love it, but I spend, you know, about 10 hours on each episode writing and researching. And we don't take advertising on the podcast, so it's all for free. And again, don't get me wrong, I love it. I'm not complaining. It's my favorite part of my job. But I did need to reprioritize when the second baby came because I wanted to make sure I was giving my attention to the EVLO membership and my family first and foremost. But I've heard from so many of you that you miss the podcast and I miss it too. So stay tuned because we'll be doing something a little different, something we've never done before, coming up in about a month or so. So make sure you're subscribed to the podcast so you don't miss it. I wanted to do this episode kind of randomly because a new study came out that challenged the way I've been speaking about calorie burn. One thing that is extremely important to me is staying as evidence based as possible. This industry can be extremely dogmatic. I personally watch people in the fitness and women's health world get questioned by the scientific community about their beliefs. And instead of updating their audience with newer, more accurate information or saying, hey, I didn't have this information then, I have it now, and here's how I'm changing how I'm educating things. Instead of doing that, they double down. And to me, this doesn't serve anyone. Doubling down on antiquated beliefs is exactly how we stay stuck and don't change or improve. And the reality is that science is continually evolving. So in my opinion, you have to do this in order to continue to give reliable, good information to your audience. So that brings me to what I want to talk about today, how we burn calories. In this episode, we'll unpack two seemingly conflicting papers. One that found that calorie expenditure is constrained, and a new study that found calorie expenditure is additive. I'll explain where I think the truth lies and we'll discuss what these findings mean for you. If your goal is body recomposition. My goal is to help you understand how this updated science fits into real life so you can train smarter, not harder. So the old theory of how we burned calories came from a study from Herman Poncer, and he hypothesized that energy expenditure is constrained, not additive. For years I've referenced this research by Ponser and it's been game changing for me. His team studied over 300 individuals and found that as we increase the daily activity, our total daily energy expenditure eventually plateaus. In other words, when we burn more calories through movement or exercise, our bodies borrow from other systems to stay within a total daily kind of calorie budget. Poncer's group theorized that systems like digestion, reproduction and immunity might slightly downregulate to compensate for increased activity. For example, if you added 100 calories worth of activity, your body might quote, unquote Save 100 calories elsewhere, keeping total energy expenditure constant. They see that this compensation doesn't happen at low to moderate levels of activity, but once you start adding a lot of activity, your overall calories begin to plateau. According to a graph from their paper, this plateau tends to occur around 800 active calories per day on average. This is a number I've referenced in various podcast episodes and in social content. And honestly, these findings were game changing for me personally. For me, 800 active calories really isn't that much according to my aura, which we know isn't super reliable, but it's the measure that we have. Around 800 active calories per day is a 30 minute walk, my ELO class, and then just the rest of my daily activities. It's fairly easy to hit that number. When I learned calorie burn is constrained, not additive, I stopped saying seeing exercise as a way to earn a meal or erase a meal because it didn't seem to be very effective anyway. I got off the hamster wheel of more and that feeling of never having done enough. I stopped feeling guilty for taking recovery days. I stopped optimizing for calorie burn and started optimizing for the stimulus to build muscle. For the first time in my life, I started separating food from exercise. I started taking more responsibility for my nutrition and all of these shifts are ultimately led to better results and my body felt less worn down. I saw better results because my workouts were actually building muscle. I was optimizing for hypertrophy, which means mechanical tension was more important than exhaustion or calorie burn. I saw better body composition changes because I took responsibility for my nutrition. I definitely indulge in my favorite foods, don't get me wrong, but I do so consciously. I never tell myself I'll just eat whatever I want because I can go burn it off later. My body feels so much better because I'm not endlessly grinding it into the ground in pursuit of burning as many calories as I can. To me, I had to really learn the science of metabolism and how we burn calories to make this shift. And it was extremely beneficial for my mental health, my results and how my body felt. Because this was so transformational for me. I talk about it often on my podcasts and on other podcasts where I've been interviewed. Then last month, In October of 2025, a new study was published that completely challenged this whole thing. A study was published by Howard and colleagues that looked at 75 individuals in the US who represented a wide range of activity levels. Some were sedentary and some were running six miles or more per day. It's important to note that the people they studied were weight stable, meaning they were fueling to replace their calorie burn. They were eating at their maintenance calories so they were not losing or gaining weight. They measured energy expenditure and activity. They also measured biomarkers for immune, reproductive and thyroid function, which I thought was really interesting. They were looking for this downregulation that Poncer theorized was happening as people began to burn more calories throughout their day. To my initial disappointment and quite frankly confusion, the results of this study directly contradicted Poncer's findings. They found that, number one, energy expenditure increased linearly with activity. There was no evidence of a plateau. Number two, there were no signs of compensation in other systems. When they looked at those biomarkers of immune, reproductive and thyroid function, they found no change as people increased their activity. And number three, unlike Poncer's theories, they found no borrowing from these other systems in order to afford their increased activity. In short, calorie burned appeared additive, not constrained, at least under the conditions they studied. So what's going on? Why are the conclusions of these two studies so different? Ponssert's research involves over 300 participants, many of whom lived in diverse environments and were not necessarily eating at maintenance calories. In other words, some of their participants were likely in calorie deficits while others were in calorie surpluses. Howard's study, this newer study, on the other hand, specifically examined weight stable individuals, people who were eating enough to replace what they burned. That detail matters because if you're in a deficit, your body has less available energy. So compensation or this down regulation that Poncer was theorizing is more likely. If you're fueling to replace the calories you burned, you might be able to increase your calorie burn more linearly. So it is possible that both of these studies are quote unquote right, depending on the context. At very high sustained activity levels, like multiple hours of training per day, or during calorie deficits, some compensation probably still occurs. But for most people training moderately and eating enough, calorie burn appears mostly additive. So if you're trying to body recomposition, if you're trying to lose fat while building or maintaining muscle, how do you interpret these findings? As far as activity, you still need to be loading muscles close to failure to at least maintain muscle mass. So that weight loss comes from fat, not muscle. You also want to stay overall active. To keep your energy expenditure high, I recommend 150 minutes per week of light to moderate intensity cardio and you could do whatever you like. I just walk. As far as fat loss, that's still primarily the role of diet. We see from many other studies that adding exercise without diet changes doesn't account for much weight loss. You simply can't outrun your fork. Even if calorie burn is more additive than we thought. But should you add more activity beyond that 150 minutes, given that energy expenditure may be more additive than we thought? Here's the thing, you can if you want. If you feel like you're recovering, adding too much activity may influence your recovery. And recovery is crucial for body recomposition and just overall health. Overdoing it with a lot of exercise will run you down and make your workouts less effective. Overall. When you're fatigued, achy and sore from a lot of prior exercise, your performance so how much you can lift and how well you can lift will go down. That means you're not giving your muscles the proper stimulus to grow. In other words, you're adding more but getting less. So just to wrap all this up, I will no longer be referencing that 800 active calorie number because it seems like it may just not be an accurate picture of what's going on. However, I still don't recommend tracking calories burn in your workouts or optimizing for calorie burn for for a few reasons. Number one, a muscle building workout is more important for body composition. It keeps protein synthesis high so that weight loss comes from fat, not muscle. But muscle building workouts typically don't burn many calories, so you could feel like your strength training workout wasn't quote unquote enough if that's the measure you're using. Number two, fitness trackers are highly inaccurate. If you're tracking food and entering a 500 calorie workout into something like My Fitness Pal, that could be overestimating your total burn and you may unintentionally intentionally eat in a surplus. Number three, Most importantly, it can be a mental challenge when you optimize for calorie burn, we stop using exercise for health and start using it for punishment. Although the findings of this study challenge the way I've typically spoken about calorie burn, I still believe that we need to get away from the hamster wheel of doing more exercise isn't effective as a calorie eraser. We see from various other studies that it simply doesn't work, especially long term. When you shift your focus from exercise as burning towards exercise as a stimulus for building, you'll see the results you're looking for feel so much better physically and get the mental relief from the never enough mentality that plagues so many of us. All right, that is it. Hope this was interesting. Again, make sure to subscribe to the show because we have something coming very soon and we will see you all next time. Bye for now.