

Phys Ed: Why Doesn’t Exercise Lead to Weight Loss? - yangyang
http://well.blogs.nytimes.com/2009/11/04/phys-ed-why-doesnt-exercise-lead-to-weight-loss/?em

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matthew-wegner
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
"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.

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tjogin
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.

~~~
gamble
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
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.

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diN0bot
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
> 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 :(.

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patrickryan
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.

~~~
spudlyo
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.

~~~
patrickryan
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.

~~~
spudlyo
Given the choice between the following two snacks:

1\. A single 0.6 oz Reese's peanut butter cup.

2\. A large apple

By your logic, choosing the healthy apple will help you lose weight because it
is not "crap", unlike the candy. However a large apple has 110 calories
whereas a single Reese's peanut butter cup has only 88.

For the purposes of losing weight the Reese's peanut butter cup is the better
choice. Arguably the apple has a better nutritional value, but that's not what
we're talking about.

~~~
xcombinator
I would choose the large apple. You know, the body is not stupid, eating 110
kcal doesn't mean storing fat.

In fact, Apple(look at the nutritional values):
<http://en.wikipedia.org/wiki/Apple> \- Sugars 10.39 g \- Fat 0.17 g

Peanut: <http://en.wikipedia.org/wiki/Peanut> \- Sugars 0 g. \- Fat Saturated
9 gr!! \- Fat monounsaturated 24gr!! \- Fat polyunsaturated 16gr!!

Maybe that doesn't tell you anything but 100 gr olive oil has more calories
that 300gr of sugar.

Eating apples is natural for human beings,like many other fruits, eating
peanut butter is not(apple has a lot of water with their sugar what makes it
easy to process, and converting its sugars to fat would take energy).

They are other reasons for storing fat, e.g cold protection and cell and
arteries protection from acids(produced by sugars burning).

The calories approach is an oversimplification.

~~~
Evgeny
>Eating apples is natural for human beings,like many other fruits

With a small correction that eating apples that were not bred for sweetness
and did not contain as much fructose as today's apples is natural. Therefore,
there is such thing as too many apples (and fructose is probably not better
than glucose or sucrose in any way).

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jfoutz
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.

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

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gamble
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.

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michaelneale
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.

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yesimahuman
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.

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

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

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rarrrrrr
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.

~~~
zackattack
> 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

~~~
holygoat
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.

~~~
zackattack
This doesn't address my criticism. I've _never_ read that training in the
morning provides a superior metabolism boost.

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

~~~
yangyang
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>

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bcl
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
Rush Limbaugh is fat.

