Excellent post. I swear by my walking pad for this reason. Much of my life is now virtual over the computer. Merely by walking while doing calls I accumulate an extra five miles per day on average I otherwise would not have had. One of the best investments I have ever made.
Great post! I always quote whomever it was (can’t remember the source; maybe you?) that noted, “I can burn 600 calories in an hour with exercise. I can consume 600 calories in 5 mins with a single 20 oz frappa-mocha-chilly-whippy* drink. Caution advised.”
Anecdotal evidence from my own life suggests these scientists are both partially right.
After an especially grueling workout/run I have observed myself being more sedentary and less fidgety as my body recovers. I would guess this would lower my basal metabolic rate accordingly.
Likewise, when I'm moving around all day at a low level for my job as a contractor, and throw a modest session of weightlifting or a hike on top...I can put down some major food while not gaining weight.
I've very rarely tracked calories, however, so it's anecdotal evidence at best.
Also, I agree that calorie deficits may lead to longer recovery times.
The only times I've been injured is when I'm trying to cut back food intake to drop some extra weight for a race while increasing my mileage.
Great insight. Interestingly, the times I’ve lost the most weight were when I wasn’t very active — usually due to burnout, illness, or injury — and just focused on nutrition. The downside was that it required strict dieting (I have a massive appetite), and I’d end up looking softer as a result. As Dr. Ted Naiman notes, we all have the appetite of someone who’s at least moderately active, so it makes sense to keep our activity in line with that if we want to sustain a lean body composition. Still, I think there are diminishing returns once activity goes beyond moderate levels, largely due to the compounding fatigue from training, dieting, and daily stress.
1. Glad to see an acknowledgment that the Hadza (or any remote tribe) isn’t necessarily the gold standard for all physiological measurements.
2. Love the ending and seeing that yes, in exercise science, it’s often still theory, and theories adapt and shift over time.
Ultimately we don’t need to eat like the Hazda or be like an indigenous tribe, nor should we get whiplash with every new scientific nugget. Find what works best to be your healthiest and happiest (even if it’s harder than it looks). 😁
I've been doing the daily weigh in for years. When doing an especially big effort I'm looking for my weight to be the same the next day as a guide I've eaten and drank enough.
This weekend after a 5k on Saturday and my first marathon on Sunday I was actually up 1 lb :)
I swim for 60-90 minutes five days a week and lift weights two days a week. To counter increased hunger, I take this monoamine neurotransmitter precursor product that blunts appetite and cravings for sweet and starchy food.
LOVE the "what this means for you section". Actionable and helpful. Appreciate the added point about the kind exchange on x....be the change you want to see.
The constrained energy compensation model is fascinating, though I’m still not sure what to make of it given all the conflicting evidence.
Anecdotally, I’ve found that exercise helps me manage my weight, mostly because it keeps my appetite in check. That said, I have to be careful when I start training hard because I tend to justify eating like an athlete even though I’m no Michael Phelps.
I think the only way to make exercise stick long-term is to make it necessary, enjoyable, and/or built into your environment. Otherwise, it’s all too easy to end up as one of the many ex-active people out there.
After I got back from my hike, I had to be really careful to not continue eating as if I was hiking 25 miles a day. That gets a lot of endurance athletes in trouble: Once high volumes of training stop, they continue eating like crazy.
Great post, Michael!. I do buy the 'immune tax' perspective from Ponza with the Hazda, but not our typical clients. 😊
As a Coach, for my clients who permanently lost fat, got healthier, stronger and fitter, they shared these behaviors:
1. they definitely increased NEAT via every opportunity [chores, stairs, parking spots, carrying stuff, etc.]; tracked steps only.
✔️one stellar example was a 40 yo client with DM1 and HTN, slightly OW who worked in a cubicle stuck to his computer; he changed jobs, became a pre-K Teacher [never sat]; lost weight and DM and HTN stabilized to healthy; guessing his steps went from minimal to 15K+. This was not intentional. He did not change his diet which was pretty good at the start.
2. Walked at least 5X/week for 30:00+ in addition to NEAT.
3. Resistance trained 2X per week.
4. EXTREMELY IMPORTANT and under-studied; these clients did NOT focus on exercise for weight loss and/or calories; I coach the Deep 6 behaviors: the WHAT, how much, how fast, when, where and why they eat and drink, while breaking 'behavior chains.' Occupying excessive 'mind space' with food, calories, weight loss etc. IS a chronic DIStressor, and sabotages fat loss, especially in women.
5. Tracked steps, continuous walks, H20, and 'self-graded' quality, quantity and timing of meals, from A+ to F; they were given the option to track BW or use belt buckle, pants, skirt, etc.]; reviewed monthly trends along with any available blood work; several clients were weaned entirely off MEDS [statins, BP, Glucose, anti-anxiety, pain, etc.] Today, we have wearables and GLPs to assist, I repeat 'assist', in conjunction with the habits, patterns and practices that sustain a healthy body comp for decades to come.
I really loved this post and appreciate how you make scientific publications accessible to a broader audience.
One suggestion: it would be helpful to include a note or legend whenever you use graphs or figures. For example, I didn’t initially know what “RMR+DIT+OTHER” meant, so I had to look it up in the original publication. Including brief clarifications like that could further improve the readability and impact of your posts.
This study makes a lot of sense to me — but I think we have to be careful not to generalize “constraint” or “additivity” too broadly. To me, it’s less about fixed universal limits and more about trainable capacity.
Highly trained individuals have vastly greater mitochondrial density, vascular supply, and substrate-use efficiency — essentially a much larger metabolic “engine.” Their systems can process and dissipate more energy because they’ve built the cellular infrastructure to do so through training, nutrition, and recovery.
So rather than viewing energy constraint as a population-wide rule, it might be more accurate to think of it as a state-dependent ceiling that shifts upward as a person becomes fitter and more metabolically resilient.
It would be fascinating to see a longitudinal study where sedentary participants first show some compensation when starting exercise, but—after months of improved VO₂ max, mitochondrial biogenesis, and metabolic flexibility—demonstrate an expanded energy budget with less compensation. That would help bridge both models by showing how constraint can be overcome through adaptation.
I also have a theory that “constraint” shouldn’t just be viewed at the whole-body level but as a tissue- or system-specific capacity. Every organ system — muscle, cardiovascular, hepatic, neural — has its own energetic ceiling determined by how much work its cells can perform over a given time frame.
In that sense, constraint exists locally. A muscle fiber, hepatocyte, or neuron can only sustain so much ATP turnover before it needs recovery and repair. Those ceilings aren’t fixed, but they’re also not infinite — they can be raised through training and adaptation (more mitochondria, capillaries, enzymes, etc.), yet they still remain bounded by the biology of that system.
So rather than one universal metabolic constraint, it might make more sense to think of a mosaic of adaptable constraints — tissue-specific energy budgets that can expand with conditioning but always have context-specific limits. Your overall metabolic “bandwidth” is the sum of those localized, trainable capacities.
I always argued for calories in vs calories out approach but then heard a podcast with dr fung that your body will just burn fewer calories if you eat less to lose weight and even on a low cal diet, consuming anything that spikes insulin will prohibit fat burn.
But I also read your Hadza post a while ago and started to lean on just being active all day!!
Excellent post. I swear by my walking pad for this reason. Much of my life is now virtual over the computer. Merely by walking while doing calls I accumulate an extra five miles per day on average I otherwise would not have had. One of the best investments I have ever made.
The walking pad is legit! I also own one. The phrase "game-changer" gets overused a lot, but it definitely applies to the walking pad!
Great post! I always quote whomever it was (can’t remember the source; maybe you?) that noted, “I can burn 600 calories in an hour with exercise. I can consume 600 calories in 5 mins with a single 20 oz frappa-mocha-chilly-whippy* drink. Caution advised.”
*Not a direct quote, obv.
I truly appreciate the work you put into each of your posts.
Thanks for reading them!
Glad to have you back reading the audio version!
Anecdotal evidence from my own life suggests these scientists are both partially right.
After an especially grueling workout/run I have observed myself being more sedentary and less fidgety as my body recovers. I would guess this would lower my basal metabolic rate accordingly.
Likewise, when I'm moving around all day at a low level for my job as a contractor, and throw a modest session of weightlifting or a hike on top...I can put down some major food while not gaining weight.
I've very rarely tracked calories, however, so it's anecdotal evidence at best.
Also, I agree that calorie deficits may lead to longer recovery times.
The only times I've been injured is when I'm trying to cut back food intake to drop some extra weight for a race while increasing my mileage.
I stopped doing that. It doesn't work well.
Thanks for the great work you're doing, Michael.
That tracks with me.
Great insight. Interestingly, the times I’ve lost the most weight were when I wasn’t very active — usually due to burnout, illness, or injury — and just focused on nutrition. The downside was that it required strict dieting (I have a massive appetite), and I’d end up looking softer as a result. As Dr. Ted Naiman notes, we all have the appetite of someone who’s at least moderately active, so it makes sense to keep our activity in line with that if we want to sustain a lean body composition. Still, I think there are diminishing returns once activity goes beyond moderate levels, largely due to the compounding fatigue from training, dieting, and daily stress.
Two things I took away from this:
1. Glad to see an acknowledgment that the Hadza (or any remote tribe) isn’t necessarily the gold standard for all physiological measurements.
2. Love the ending and seeing that yes, in exercise science, it’s often still theory, and theories adapt and shift over time.
Ultimately we don’t need to eat like the Hazda or be like an indigenous tribe, nor should we get whiplash with every new scientific nugget. Find what works best to be your healthiest and happiest (even if it’s harder than it looks). 😁
Agreed—great message!
I've been doing the daily weigh in for years. When doing an especially big effort I'm looking for my weight to be the same the next day as a guide I've eaten and drank enough.
This weekend after a 5k on Saturday and my first marathon on Sunday I was actually up 1 lb :)
I swim for 60-90 minutes five days a week and lift weights two days a week. To counter increased hunger, I take this monoamine neurotransmitter precursor product that blunts appetite and cravings for sweet and starchy food.
https://carbsyndrome.com/product/carb-22/
Over the past three years, I have lost 30 pounds and kept it off. So far, so good!
2% wherever you go.
LOVE the "what this means for you section". Actionable and helpful. Appreciate the added point about the kind exchange on x....be the change you want to see.
The constrained energy compensation model is fascinating, though I’m still not sure what to make of it given all the conflicting evidence.
Anecdotally, I’ve found that exercise helps me manage my weight, mostly because it keeps my appetite in check. That said, I have to be careful when I start training hard because I tend to justify eating like an athlete even though I’m no Michael Phelps.
I think the only way to make exercise stick long-term is to make it necessary, enjoyable, and/or built into your environment. Otherwise, it’s all too easy to end up as one of the many ex-active people out there.
After I got back from my hike, I had to be really careful to not continue eating as if I was hiking 25 miles a day. That gets a lot of endurance athletes in trouble: Once high volumes of training stop, they continue eating like crazy.
Great post, Michael!. I do buy the 'immune tax' perspective from Ponza with the Hazda, but not our typical clients. 😊
As a Coach, for my clients who permanently lost fat, got healthier, stronger and fitter, they shared these behaviors:
1. they definitely increased NEAT via every opportunity [chores, stairs, parking spots, carrying stuff, etc.]; tracked steps only.
✔️one stellar example was a 40 yo client with DM1 and HTN, slightly OW who worked in a cubicle stuck to his computer; he changed jobs, became a pre-K Teacher [never sat]; lost weight and DM and HTN stabilized to healthy; guessing his steps went from minimal to 15K+. This was not intentional. He did not change his diet which was pretty good at the start.
2. Walked at least 5X/week for 30:00+ in addition to NEAT.
3. Resistance trained 2X per week.
4. EXTREMELY IMPORTANT and under-studied; these clients did NOT focus on exercise for weight loss and/or calories; I coach the Deep 6 behaviors: the WHAT, how much, how fast, when, where and why they eat and drink, while breaking 'behavior chains.' Occupying excessive 'mind space' with food, calories, weight loss etc. IS a chronic DIStressor, and sabotages fat loss, especially in women.
5. Tracked steps, continuous walks, H20, and 'self-graded' quality, quantity and timing of meals, from A+ to F; they were given the option to track BW or use belt buckle, pants, skirt, etc.]; reviewed monthly trends along with any available blood work; several clients were weaned entirely off MEDS [statins, BP, Glucose, anti-anxiety, pain, etc.] Today, we have wearables and GLPs to assist, I repeat 'assist', in conjunction with the habits, patterns and practices that sustain a healthy body comp for decades to come.
✅ That's what we do, Coaches!
👍⛰️
I really loved this post and appreciate how you make scientific publications accessible to a broader audience.
One suggestion: it would be helpful to include a note or legend whenever you use graphs or figures. For example, I didn’t initially know what “RMR+DIT+OTHER” meant, so I had to look it up in the original publication. Including brief clarifications like that could further improve the readability and impact of your posts.
Love all your posts, keep up the good work!
This study makes a lot of sense to me — but I think we have to be careful not to generalize “constraint” or “additivity” too broadly. To me, it’s less about fixed universal limits and more about trainable capacity.
Highly trained individuals have vastly greater mitochondrial density, vascular supply, and substrate-use efficiency — essentially a much larger metabolic “engine.” Their systems can process and dissipate more energy because they’ve built the cellular infrastructure to do so through training, nutrition, and recovery.
So rather than viewing energy constraint as a population-wide rule, it might be more accurate to think of it as a state-dependent ceiling that shifts upward as a person becomes fitter and more metabolically resilient.
It would be fascinating to see a longitudinal study where sedentary participants first show some compensation when starting exercise, but—after months of improved VO₂ max, mitochondrial biogenesis, and metabolic flexibility—demonstrate an expanded energy budget with less compensation. That would help bridge both models by showing how constraint can be overcome through adaptation.
I also have a theory that “constraint” shouldn’t just be viewed at the whole-body level but as a tissue- or system-specific capacity. Every organ system — muscle, cardiovascular, hepatic, neural — has its own energetic ceiling determined by how much work its cells can perform over a given time frame.
In that sense, constraint exists locally. A muscle fiber, hepatocyte, or neuron can only sustain so much ATP turnover before it needs recovery and repair. Those ceilings aren’t fixed, but they’re also not infinite — they can be raised through training and adaptation (more mitochondria, capillaries, enzymes, etc.), yet they still remain bounded by the biology of that system.
So rather than one universal metabolic constraint, it might make more sense to think of a mosaic of adaptable constraints — tissue-specific energy budgets that can expand with conditioning but always have context-specific limits. Your overall metabolic “bandwidth” is the sum of those localized, trainable capacities.
Have you listened to the Science in Sport podcast? https://www.cell.com/current-biology/abstract/S0960-9822(25)01129-7
This came out from Pontzer 2 days before the other study!
I always argued for calories in vs calories out approach but then heard a podcast with dr fung that your body will just burn fewer calories if you eat less to lose weight and even on a low cal diet, consuming anything that spikes insulin will prohibit fat burn.
But I also read your Hadza post a while ago and started to lean on just being active all day!!
I love this stuff!!