"The cover of the August 17, 2009 issue of TIME magazine insists that "Of course it's good for you, but it won't make you lose weight. Why it's what you eat that really counts." Turning to the feature article on Health penned by John Cloud, all I can note is that the stupid not only burns, but it incinerates all logic and sense for a five block radius." - tim from Bookmarklet

Most people do not realize that you have to exercise so much for it to have an effect on weight loss. I do not agree that the piece is stupid, quite the contrary it's probably important to enlighten people on this. Many do not have the time to exercise an hour daily (including me) that means that loosing weight must be done through diet mainly - exercise is useful, but in other ways than dieting. - Nils Reinton

the original Time article is disingenuous at best, and outright misleading on many issues. it has little or nothing to do with exercise, and everything to do with poor eating habits. it poses 'questions' like "Could exercise actually be keeping me from losing weight?" and proceeds to 'answer' them based on anecdote and 'logical reasoning.' it complete ignores any actual science. - tim

Nils - you raise the point that I think the article should have raised: exercise will make you lose weight. just not the way it has been sold to most people (30 min at a HR of 100 won't do it). and not if you eat a bag o' donuts afterward. this 'junk food as my reward for exercise' meme is endemic, and just plain wrong, and needs to be changed. - tim

I thought there was a study out that suggested that people who exercise simply eat more to cope with the energy expenditure, but were likely to overestimate how much they required, thus offsetting any weight loss through fitness gain. At least that's the story I hear when this reared it's head in the UK. The only way to lose weight is caloric restriction. http://www.fourmilab.ch/hackdie... Hackers Diet for the win :) I don't miss those 3 stone at all... - Daniel Swan

Exactly, Daniel, and the study explicitly states that they didn't give any dietary directions to them other than to not change anything. It's very likely the exercising group simply ate more. - Mr. Gunn

I don't disagree with the original scientific study. I strongly object to the misinterpretation of its conclusions, as seen in the Time article. - tim

Tim. I have now carefully read through the TIME piece (again) and I actually thought it was really good. Of course, I haven't had time to read all the references he mentions or done background check on the people he quotes, but it looks solid to me. - Nils Reinton

Nils - I am intrigued by the original PLoS article, but haven't read it yet. but there are so many flawed arguments in the Time piece, even beyond his awful setup, I hardly know where to start. he extrapolates a study done on children to adults. his entire discussion about exercise actually contributing to obesity is complete, made-up bullshit. he does quote the recommended 60-90 min of exercise per day, several days per week, but then all of his anecdotal counter statements are for much shorter periods of time (20 min jog?), or pseudo-exercise (walking around the neighborhood, climbing stairs). he takes a single news release about the positive effects of activity on cognitive function, and turns it completely around to say vigorous exercise carries no more benefit than carrying your groceries. I could go on... - tim

Tim. Why are (two rather large) studies done on children not valid to a certain extent for adults ? Besides, the obesity epidemic is striking children the hardest (very hard to loose fat cells you gained during childhood, - ref needed) so obesity in children is by no means irrelevant. There are more quotes from science professionals than anecdotal evidence IMO and I do not find the cognitive benefit study to be central to his arguments at all. Please go on, because I am still not convinced that this is not a solid pop-science piece. - Nils Reinton

I never said obesity in children was irrelevant. but biochemistry and physiology of children is different than adults, and 'daily activity' is vastly different from exercise in adults. so the connection, if there is one, between kids' activity levels and exercise to weight loss in adults seems pretty tenuous. also, I've already documented multiple examples where the author makes conclusions based on no data, or even makes up connections because they strengthen his argument, and also where he makes conclusions that are just plain unsupported by his own citations. just because he quotes scientists and references published studies does not, in any way, make his interpretations sound or reasonable. but show me the data, please, that show how exercise can lead to obesity - one of his main conclusions. (note: I exercise quite a bit, and I do not lose weight. but I'm inclined to think the story may be more complicated than just my eating an extra blueberry bar or not.) - tim

Tim. You obviously have a good handle on this subject. Granted then: his conclusion that exercise makes you gain weight is unsubstantiated and his conclusion that low intensity exercise is just as good as high intensity has not been irrefutably demonstrated yet. My take-home message from this article is still that most people believe that exercise for about an hour, two to three times a week will help you loose weight and that this belief can in the worst case even lead to weight gain. Would you agree that these are sound conclusions ? I have a genuine interest in this and appreciate the discussion we-re having - probably a lot more rewarding than if we had the same discussion over at drug monkey's. - Nils Reinton

nils - I still haven't read the original PLoS article ;-) but I do agree with you: the normal exercise regime of many adults will not lead to dramatic weight loss. that was not my take-home message, though perhaps I'm too sensitive on the subject. it is quite complex. what kind of exercise? strength training is very different from aerobic. what is your avg heart rate? as for the psychological data, I *do* agree that we need to combat this 'junk food as reward' idea - I just don't think the Time article does that very well. <shrug> (you're right, though, that this discussion is much better than on any other forum! too bad if we're losing FF.) - tim

Blogging about this on biopinionated - Nils Reinton

this may not be pretty. here's the title of the PLoS article: "Changes in Weight, Waist Circumference and Compensatory Responses with Different Doses of Exercise among Sedentary, Overweight Postmenopausal Women." mean age: 57.3 yrs. ouch. confounding factors here due to gender and age: lipid profiles, estrogen levels, hypertension... I find it very suspect to extrapolate these results to the population at large. - tim