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Wednesday, June 24, 2015

Myth Buster: Exercise causes weight loss

I think I wrote about this before on this blog, that you can't lose weight just by exercising alone. I tried it last winter, and I actually ended up gaining weight.

You see ads galore trying to get you to buy one gadget or another to lose weight. They show you a picture of the gadget, and a picture of some guy with six pack abs and say, "This could be you if you buy this product."

The truth is, that person never lost weight using that product. If fact, he probably had that six pack long before the product was ever even invented.

Truth is, it doesn't matter what product you buy, you will not lose weight by exercising alone. You have to diet. Losing weight is a matter of ins and outs. If you take in less than what goes out of your body, you will naturally lose weight.

Yes, there are advantages to exercising. I've written about them too on this blog and my asthma blog. The benefits of exercise is overwhelming, and I highly recommend you do it.  Exercising strengthens your heart and lungs, improves your immune system and makes you feel better overall.

Yet exercise alone will not result in weight loss.  It may help you burn fat faster, but it will not cause you to lose weight if you do not also eat a healthy diet.

I've always believed this, yet trying to find proof in a world dominated by marketers, and a media, that is content to have you believe that exercise is the key to weight loss so they can brainwash you to buy their products is never easy.

However, I found an article at called, " Why Exercise Won't Make You Thin," by John Cloud (Thursday, Aug. 06, 2009) that explains quite simply why exercise alone won't make you thin.

Cloud said that if exercise alone made people thin, the fact that the percentage of people exercising increased from 47% to 57% from 1980 to 2000 would result in a thinner society. Yet, the opposite is true, as America is fatter than ever before.

He said:
"The basic problem is that while it's true that exercise burns calories and that you must burn calories to lose weight, exercise has another effect: it can stimulate hunger. That causes us to eat more, which in turn can negate the weight-loss benefits we just accrued. Exercise, in other words, isn't necessarily helping us lose weight. It may even be making it harder."
He also mentions a study where 464 women were asked to maintain their normal diet. Most were told to exercise, while one group was told not to exercise.

The results:
"The findings were surprising. On average, the women in all the groups, even the control group, lost weight, but the women who exercised — sweating it out with a trainer several days a week for six months — did not lose significantly more weight than the control subjects did....Some of the women in each of the four groups actually gained weight, some more than 10 lb. each."
He said that a paper written by a group of psychologists explains why this happens:
"Many people assume that weight is mostly a matter of willpower — that we can learn both to exercise and to avoid muffins and Gatorade. A few of us can, but evolution did not build us to do this for very long. In 2000 the journal Psychological Bulletin published a paper by psychologists Mark Muraven and Roy Baumeister in which they observed that self-control is like a muscle: it weakens each day after you use it. If you force yourself to jog for an hour, your self-regulatory capacity is proportionately enfeebled. Rather than lunching on a salad, you'll be more likely to opt for pizza."
It is possible, Cloud concludes, that the recent trend to get people to exercise more has caused America to get fatter?

Originally published on 8/17/2009; edited

Further reading:


David in Houston said...

True. What is not covered in the discussion is solely utilizing weight as a measure of fitness. As you say, in general weight loss is a function of how many calories you burn in excess of you intake. The density of muscle mass vs fat should also be considered.

Muscle density is 1.06 g/ml and fat density is (about) 0.9 g/ml. Thus, one liter of muscle would weight 1.06 kg and one liter of fat would weight 0.9 kg. In other words, muscle is about 18% denser than fat. By exercising your weight can actually increase, however your ratio of lean muscle mass vs fatty tissues can improve at the same time.

An example at its extreme would be bodybuilders- if you simply look at their height vs weight they are overweight. Increased muscle mass also relates to increased baseline metabolism, and as a result a higher number of calories burned per day excluding exercise. So the answer is no, exercise is not making America fatter- excess caloric intake is. So eat smaller portions (don't super-size it).

Freadom said...

It's funny you say that, because I was just discussing that with a friend. I suppose a better question is: do you want to be more fit, or do you want to lose weight?

Also the BMI calulation fails to recognize muscle.

David in Houston said...

Exactly. Obsessing over weight obscures the more important issue. Are you better off as an individual that is at a "good weight" but scores poorly in terms of fitness, or as someone that is fit but weighs more than their "ideal body weight"? Perhaps the questions should be "How can I increase my level of fitness?" and "Is my current weight associated with other indicators of poor fitness?" Weight and fitness are not mutually exclusive- they should be evaluated in relationship to each other. Personally I would rather be fit and a bit "overweight".