Phys Ed: Why Doesn’t Exercise Lead to Weight Loss?

http://well.blogs.nytimes.com/2009/11/04/phys-ed-why-doesnt-exercise-lead-to-weight-loss/?em

by yangyang • 17 years ago

33 48 17 years ago

well.blogs.nytimes.com

diN0bot• 17 years ago

first, are the overwhelming studies focused solely on obses people, or other people as well? i could imagine obese people and "normal" people have significantly different diet and eating habits.

the growing wisdom is that the more you exercise the hungrier you get. that's fine. the problem is that then people feel like they have a free pass to splurge. i suspect that kind of habit is greater in obese people.

edit: personally, i feel less hungry after exercising, and more in control of what i eat. when i don't exercise, it is often related to some negative change in my life (sick, deadline, down-ness), and i'll tend to either eat much less or search for unhealthy food.

i've been the exact same weight for the past decade, so calorie in/out-wise i've settled into an moving routine. of course, where those calories sit has moved around. the kinds of sports i play effect where my muscles and excess fat are. my trimness and energy levels change, even if my weight does not.

rmanocha• 17 years ago

> edit: personally, i feel less hungry after exercising, and more in control of what i eat.

Same here - the days I workout/play a sport, I end up eating less (this might also be 'cause I end up drinking a lot more water). On the days I don't do either, I find myself constantly hungry and snacking at regular intervals - plays havoc with my calorie monitors :(.

rarrrrrr• 17 years ago

Umm, the exercise they cited was aerobics, which is well known not to provide a lasting all day long metabolism boost. Nothing new here.

Resistance training however typically provides a metabolism boost for the rest of the day (i.e. until you next sleep.) That's why it's helpful to work out in the mornings.

However, I would certainly support the conclusion that exercise (even resistance training) while continuing to eat junk food will not result in significant health improvement.

zackattack2• 17 years ago

> Resistance training however typically provides a metabolism boost for the rest of the day (i.e. until you next sleep.) That's why it's helpful to work out in the mornings.

Source please? I've never heard this

gcheong• 17 years ago

And would it make sense for our bodies to do this? I can see expending energy on repair and muscle growth, but why would our bodies maintain a higher metabolic rate if there were no reason to given that the tendency seems to be to conserve energy as much as possible?

Deestan2• 17 years ago

It rather sounds like something from a D&D rulebook.

holygoat2• 17 years ago

The "rest of the day" assertion is commonly observed by people training, but I don't have a link handy.

Here's one that shows a longer-term effect:

http://jap.physiology.org/cgi/content/abstract/85/2/695

Essentially, incorporating resistance training in your exercise regime raises your basal metabolic rate.

This is quite well studied, and makes sense.

bcl• 17 years ago

Rush Limbaugh has been saying this for years. He doesn't exercise (unless Golfing can be considered exercise), but uses various diets to loose weight with a fair degree of success. An obese person just can't burn enough calories to make a difference. The input has to be reduced.

duh• 17 years ago

Rush Limbaugh is fat.

jfoutz• 17 years ago

When I've been slacking, then I start running again, I get hungry. I'm curious how they prevented people from eating more than normal after exercise. As they pointed out, a sports drink will more than cover the calories lost. On workout days, I would bet, people were taking in an extra 1k or more calories.

yangyang4• 17 years ago

I tend to find (and have read that this is a common occurance) that long, hard runs actually suppress my appetite.

barryfandango• 17 years ago

Better question: why are we so focused on weight loss instead of health and fitness?

yangyang4• 17 years ago

The probability of developing some cancers is much higher in people that are overweight. It's difficult to be overweight and healthy.

http://www.google.com/search?q=cancer+overweight

Deestan2• 17 years ago

Probably because weight loss is "cheaper", i.e. it doesn't have to take from your precious time. And don't forget that being overweight brings along a few health problems, so weight loss automatically leads to improved health.

orangecat• 17 years ago

Weight loss makes you more attractive, "health and fitness" provides uncertain statistical benefits that mostly occur many years down the road.

matthew-wegner• 17 years ago

Here's why they didn't lose weight:

The cycling was deliberately performed at a relatively easy intensity (about 55 percent of each person’s predetermined aerobic capacity).

Body recomposition isn't a game of calories; it's a game of hormones. It's well documented that high intensity effort is required to increase levels of human growth hormone, which leads to fat loss ("afterburn", as the article calls it).

This is easily found in existing medical research. Quick Google turns up this, but there are many others: http://jcem.endojournals.org/cgi/content/abstract/75/1/157

GH did not increase significantly from preexercise baseline during low intensity exercise

[...]

A minimum duration of 10 min, high intensity exercise consistently increased circulating GH in adult males.

So HGH is released relative to a workout's intensity, not its duration. You'd be better off with 20 minutes of high intensity workout versus 3 hours putzing around on a stationary bike.

A hormone-centric mindset will get better results with diet, too. Your hormonal response to some piece of food is much more important than its caloric count. This may be slightly conspiratorial, but I think the food industry fights against this viewpoint. They want you to think you can still lose weight if you eat their shitty 100-calorie snack packs full of crappy corn syrup and whatever because, hey, it's 100 calories, right? Woe betide the food industry if people actually start caring what they're eating instead of just how much...

Alex3917• 17 years ago

"You'd be better off with 20 minutes of high intensity workout versus 3 hours putzing around on a stationary bike."

You actually do burn a lot of fat just cruising at 155bpm or whatever, it's just that it takes about 90 min for your body to exhaust the energy supply in your liver. At this point your percentage of energy coming from fat increasing, which is necessary not only to lose weight but also to get the full benefits of cardio training. That's why elite athletes always go for at least 90min when they do cardio.

Note though that you want to eat something every 45min or so and also drink something with electrolytes or else you risk 'overtraining', which doesn't actually come from training too much but rather from chronic glycogen depletion.

patrickryan3• 17 years ago

How to lose weight:

1. Eat clean

2. Eat less calories

3. Burn more calories

Exercise alone will not help you lose weight if you are eating bad foods. Your diet is 70% of losing body fat. Burning calories will get you to your goal much faster.

spudlyo3• 17 years ago

I disagree with your first point. You can eat nothing but refined sugar, and as long as you expend more energy than you consume you will lose weight.

patrickryan3• 17 years ago

From my experience, no amount of exercise will help you lose weight if you are eating crap. The only way I lost 25 lbs was to eat clean and exercise at least 3 times a week.

jlees2• 17 years ago

I guess this was mostly low-intensity aerobic exercise so not so relevant, but the factor of muscle gain isn't to be overlooked either. If I trade 1kg fat for 1kg muscle, my scales are disappointing, but I'm ultimately healthier.

tjpick• 17 years ago

but since muscle is more dense than fat you'll be thinner too.

By weight-loss people generally seem to mean size-loss anyway.

tjogin2• 17 years ago

My personal observations: a lot of people who think they exercise actually do not.

While they may be physically located in a facility that describes itself as a gym, and while they may be moving their body and limbs to some degree, they don't make an effort. They don't put in any work.

Walking on a treadmill for fifteen minutes, using about the same amount of energy as it took them to even get to the gym is not sufficient.

Using machines or free weights at about the weight of the gallon of milk they habitually lift every day is not sufficient.

You have to put in the work. Whether you want to burn calories or build muscle, there is no short-cut to get around this fact.

Another wonderful mistake is to not work out properly because you don't want to expose yourself to the risk of accidently putting on too much muscle mass — sort of like not walking home too fast because you don't want to accidentally break the landspeed record.

gamble2• 17 years ago

The average man living a sedentary lifestyle needs about 2000-2500 calories a day to maintain his weight. Another man, doing 8-12 hours of hard physical labor per day, needs about 3500-4000 calories.

The truth is that what most people think of as 'exercise' is an order of magnitude less than what you'd need for physical activity to have a significant effect on your weight. A candy bar or frappucino easily replaces the calories burned in a gym workout, no matter how high intensity it is.

unalone• 17 years ago

When I stopped eating junk food I was astonished at how much I could snack and not gain any weight. It took almost no dieting to start to drop weight.

HeyLaughingBoy• 17 years ago

Pretty much spot on.

I have a friend (a one-time business partner, actually) who used to work as a gym assistant in exchange for a "free" membership. Her job was basically to teach people how to use the machines and give some basic pointers on form. She constantly had women coming up to her asking, "You have a really great body. I need to know what kind of exercise I should do to look like you, but I don't want to sweat."

Her response was usually a more polite version of "WTF!!! You're not going to get any benefit from the exercise unless you actually DO WORK!!!" Suffice to say that once they realized how much effort (and sweat!!) she had to expend to maintain her rather muscular physique, they lost interest.

yesimahuman• 17 years ago

A lot of people underestimate the value of weight training. Gaining muscle increases your metabolism. And really, you aren't going to look anything like a bodybuilder. And if you want to, you already know what kind of work that requires.

gamble2• 17 years ago

Unfortunately, most people don't like the idea that the only way to lose weight is to control your diet. They would much rather believe that an hour or two of exercise per week, or eating 'good' foods, will let them eat as much as they want and still lose weight. The reality is that if you want to lose weight, you're going to be hungry for a while - it isn't pleasant, but that's the way the body works.

I lost 50lbs by controlling my diet, so anecdotally I know it works. But try explaining that to people, and it's like talking to a brick wall. It's a bit depressing to see the amount of unscientific nonsense spouted on this thread. If HN is this bad, it isn't hard to see why weight loss nonsense is ubiquitous in the popular culture.

michaelneale• 17 years ago

What about forgetting about weight. Unless you are a boxer or a jockey who cares. Measure size: waist in particular. It doesn't lie (and isn't affected by hydration), or lap times, or weight you can lift. It seems the focus on weight is picking the wrong variable to optimise for.

Phys Ed: Why Doesn’t Exercise Lead to Weight Loss?

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