14 Comments

Very interesting read, thank you. Has there been any other studies supporting this new model? Was his original paper peer reviewed? Intrigued to hear what other rebuttal there is in the science world surrounding this as its pivotal for a modern PT approach to weight-loss and behavioural change.

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It was peer reviewed yes. And nothing that I'm aware of. I've seen Pontzer post some more recent systematic reviews of exercise trials in specific patient populations to support his model, such as in people with severe heart problems. But obviously the exercise is very low-intensity and isn't expected to contribute much to TDEE at all. So same old story really. I might write up a more detailed critique of the model for peer review, if I get time.

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Also here after watching Kurzgesagt and thinking they're usually very reliable and well-referenced, but that the point doesn't square with my own experience. Thanks for the article, really clear and helpful in pointing out the flaws in Pontzer's (or Pretzel's!) work

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I'd never heard of Kurzgesagt but they seem very reputable. Shame. It's good to have you here.

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"Kurzgesagt – In a Nutshell" has a new video about this topic: "We Need to Rethink Exercise – The Workout Paradox." I watched it in the morning and saw your article hours later. Their claims are wild (or lets say Pretzel's claims, since he is one of the experts tow experts they consulted, and the points made are similar to his). I didn't know In a Nutshell is not trustworthy. ):

I really like the voiceover. I am somewhat lazy and don't like reading.

You once had an article called 'A Critical Analysis of Eggs and Cardiovascular Disease.' I would really like to know more about eggs. Can I still find the article somewhere?

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Thanks for pointing out the video. I don't know if you meant to say Pretzel but that caught me off guard, hahaha. O yes, eggs, that was a very long article by Matt Madore (Twitter: @Mattmadore576). I'd contact him directly to ask for a copy as it's possibly updated since I published on the old site.

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I've also started seeing this claim about exercise and weight loss getting more popular.

I won't lie though, the weight loss reported from the 3 long term trials seems underwhelming. If you just randomly told me that someone had been exercising for ~9+ months for weight loss, I think I would've been expecting more of it. Something closer to like 10kg. (Roughly -0.3kg/wk, with some flactuations here and there)

So maybe the issue that Ponzter et al are trying to fight is that a lot of us overestimate the effect of exercise on weight loss in our priors.

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It's a different question to ask whether exercise meets people's weight loss expectations. Pontzer goes beyond that to argue little to no benefit period, which is the focus of this article. I can touch on more going forward, but remember that the average long-term results from diet trials is also underwhelming, not that dissimilar from exercise trials with moderate-high doses, and also does not match people's expectations. Is that a good reason to argue dieting leads to little to no weight loss? I don't think so.

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Funny thing is some people now do argue that diets don't lead to weight loss. I think maybe it's because of the regain that happens for some participants.

Good point about the expectations being a different question to one of whether exercise leads to higher energy expenditure.

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Yes and my response for diet and weight loss would be similar. It depends on the diet. Plenty of diets lead to long-term weight loss on average, with massively varying individual outcomes, but summarising the effects of 'weight loss diets' is not impressive in the slightest. Same with summarising exercise trials here, most of which average like 100kcal burn a day max, lol. I don't know what people are expecting.

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If a hobbyist is primarily focused on muscle maintenance/building, let’s say full body training every 3rd day or 2-3x/week, how far can/should he go with calorie burning activity on top of that to enhance fat loss without negative consequence for muscle (hours/week) and should it be moderate, about an hour long or rather more intense, interval based, 30 minutes/session? Thanks.

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Hi Ondra, exercise programming to that level of detail is not my area of expertise unfortunately. You can definitely work in some cardiovascular exercise on top of your full body training without consequences to muscle mass and recovery though – to what extent, I'd discuss with someone with more experience in that lane.

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"I think Pontzer is wrong. Not completely wrong ... but wrong enough". This is the quote!

Shaun, given the Tanzanian cohort will be of a similar (lean) body composition (I would assume), is using FFM in any way more valid or insightful than BW?

Does he touch on or mention the fact the (exaggerated) effect seems to be driven by gender which is likely mediated via muscle mass?

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Not that I've seen? And I would consider adjustment for either variable to be equally invalid in this case. FFM is a better predictor of TDEE than body weight, though, if that has anything to do with what you're asking.

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