Phys Ed: Why Doesn’t Exercise Lead to Weight Loss? | Hacker News Reader

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

well.blogs.nytimes.com

33 pointsyangyang48 comments

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...

"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.

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.

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.

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.

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.

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.

> 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 :(.

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.

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.

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.

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.

Yes, I would choose the apple if I had the choice between the two. The Reese's cup is less caloric, but high in sugar and fat. The apple also has a considerable amount of sugar as well, but has health benefits. Also, the apple will keep you full much longer than the Reese's. Let's face it, who only eats just one Reese's? The key is balancing eating good foods with less calories.

Also, I think it is important to not to focus on "losing weight", but living a healthier lifestyle.

Losing weight is something you can quantify and measure. Living a healthier lifestyle is fuzzy and open to interpretation -- allowing you rationalize almost any behavior you choose. For certain kinds of people the certainty of calories in vs. calories out is comforting, especially in the world of weight loss where feel good reasoning and pseudo science are everywhere.

No. Stop rationalizing that all there is to a Reese's cup is just calories. A healthy lifestyle has quantifiable metrics in regards to the levels of cholesterol, processed sugars, vitamins and aminoacids you should consume daily.

The food you consume also interacts in complex ways that go beyond what has been formally quantified, but a casual observation of people who eat leaner foods and vegetables instead of processed sugars and dairy products is pretty good circumstantial evidence. There's a reason why dissociative diets can produce different effects on your body even though by the end of the week you may have eaten the same in terms of the amounts of calories and nutrients as other people.

I have two personal observations in favor of that: I have psoriasis, and the level and redness of the rashes is directly correlated to my daily intake of fruits and abstinence of coffee. I also know several people who are healthy vegetarians who have been keeping insanely good dieting regimes for several years, and it's remarkable how good their skin looks in comparison to other people of their own age, less wrinkled and more elastic (not being a scientific observation, my sample size is still large enough to be adequately convinced personally).

You realize of course that choosing that weight lose is the most important metric is just another form of rationalization. If you take a step back to first principles and start with a reasonable goal such as "I want to feel better and live longer" then zeroing in on losing weight is not necessarily the most effective path. For obese people it might be, but for normal people getting regular exercise and eating right (which varies by individual) will have a much more positive effect than obsessing over weight.

Furthermore, telling people to count calories and not worry about the quality of what they eat is just opening the door for that same destructive human behavior of eating whatever crap they want, just in limited quantities. This is not the road to health. No amount of engineering mentality will get around the fuzziness of health or the stubbornness of human nature. Fortunately people are capable of being honest with themselves to varying degrees, and it is possible to improve one's health by a commitment to exercise and healthy eating.

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.

>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).

You compare nutrition of apples with peanuts, then say it's natural for humans to eat apples. It's natural for us to eat peanuts too - compare the nutrition of apples with peanut butter if you want to make that argument.

Bioavailability is important.

Well that's your experience, obviously you weren't exercising more than you was consuming.

I easily lost over 20lbs whilst regularly eating McDonald's (by regular I mean I managed two big mac & fries & large soda, sometimes multiple times a week). Plus at the time I was consuming tons of empty calories in the form of beer and alcohol.

I didn't exercise either, I simply did my job. 8 hours of hard menial work, and frequently carrying exceptionally heavy weights up and down stairs. It's estimated that for an athletic person, 9 stairs = 1 calorie. Basically you burn 1 calorie every 5 1/4 feet if you're a ~120lb person. At the time I was ~240lb and I was carrying ~70lb of materials and ~20lb of tools up a 15ft staircase.

Basically I burnt 9 calories every trip upstairs and I likely made over a hundred of them in a day, every day 7 days a week. I lost that 20lbs in two weeks.

So from my experience, you can literally eat the most disgusting greasy food and load up on hundreds of empty calories because if you actually work you will find a way to burn off those calories. Assuming 1 hour of mild exercise means you can eat anything you want is absurd. I 'exercised' over 8 hours a day (frequently it ran to 10 hours) and it made me a shit load of cash . . . suck that gym membership!

What was the job?

If energy out > energy in, and the amount of water inside you is constant, I fail to see how you can put on weight.

What you don't see is that the amount of "energy in" is not regulated by typing a number into a computer, but how hungry you feel. And clean food makes you a lot less hungry for the same amount of "energy in", which makes you less likely to overeat the prescribed amount of "energy in".

You're falsifying the argument. We're not talking about "what you can eat that will make you feel less hungry and so will help you stick to your diet", we're talking about the simple equation of energy out - energy in.

In my experience, you can eat crap, drink beer, etc, and still lose a large amount of weight. You just have to know how much crap you're eating and keep the quantity down.

No. You are not understanding the difference between humans and computers. The equation simply makes no sense for humans, it is an ideological statement that only makes sense for machines (and humans living like they're a computer).

What matters for most human beings are how hungry they feel, because that is what controls how much energy that they take in.

Oh, and you forget that the "miles per gallon" for a human body is not constant. When the body gets less energy, it can improve the milage.

  > What matters for most human beings are how hungry
  > they feel, because that is what controls how much
  > energy that they take in.

No, what matters most is how much energy they take in, and how much they burn. You're simply claiming that if people are hungry they will eat more. That's just saying they'll take in more. You're also saying that the body will "get better mileage". That's just burning less.

The long and the short is that if you absorb less energy than you burn, you'll lose weight. There are a shed-load of "strategies" to try to stop you from feeling hungry while you do this, but the truth is that if you want to lose weight you have to starve yourself. If you accept that, then you can make whatever trade-offs you like.

Of course the body is a complex thing, but the physics is easy, and understanding the physics makes the mental side easier too.

> Of course the body is a complex thing, but the physics is easy, and understanding the physics makes the mental side easier too.

I think this is actually quite profound. So many people don't understand the (relatively simple) physics of it, they try out things left and right — for a week — because they read it in a magazine.

There's also the case of short term versus long term energy spikes causing hunger and plenty of other psychological factors. On paper, yes, if you eat 100 calories of sugar a day versus ten apples, you'll lose more weight. But humans are not a transparent in vs out system. Plus there's also the fact that if you eat too little, your body reacts differently, making it nothing like the straight-line effect (eat 100 cal less, lose X; eat 1000 cal less, lose 10X) that a simplistic view would expect.

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.

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

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.

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.

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.

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.

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

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

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.

> 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

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.

This doesn't address my criticism. I've never read that training in the morning provides a superior metabolism boost.

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?

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

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

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

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

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.

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.

Rush Limbaugh is fat.

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