Saturday, August 8, 2009

Article: Why Exercise Won't Make You Thin- Time Magazine

The original article appears here:
Why Exercise Won't Make You Thin

This article is definitely worth a read, since it flies in the face of what almost all of us have come to believe: In order to lose weight, we have to exercise.

Author John Cloud asks the question, "Could exercise actually be keeping me from losing weight?" In my mind, there is no solid yes or no answer to that question.
"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."

I think it is fairly apparent to anyone who has exercised that, yes, working out does increase your hunger level. Your body naturally wants to replace the calories it has lost, i.e., maintain a neutral energy balance. But we know that in order to lose weight, we need a negative energy balance. We must expend more calories than we take in.

So if you go to spin class for an hour and then hit up Dunkin Donuts for a cream-filled donut and a Coffee Coolatta, you've not only undone all your hard work in spin class, but also undone tomorrow's class and half the next day's too. If, on the other hand, you go home and eat a big salad drizzled with a little balsamic and olive oil, you won't undo your hard work, and you'll feel extra virtuous too.

The other problem is sports drinks. In case no one let you in on the secret, no amount of Gatorade will ever allow you to dunk it like Shaq, drive it like Tiger, or bend it like Beckham. Sorry to douse your dreams with a cold bucket of, uh, Gatorade. The fact is, for workouts of an hour or less, all you need is water for rehydration. (American College of Sports Medicine, 2007) Unless you are doing intense workouts of over an hour (e.g., marathon training, spending the afternoon cross-country skiing), save your money and your calories by drinking water. Regular Gatorade has 50 calories per 8 oz. So if you chug the 32 oz. bottle while you walk on the treadmill for 30 minutes, you've consumed about 200 calories, and expended only about 150. Whoops! In that case maybe exercise IS making you fat! (I used the calorie calculator here, using a 150 lb. person walking a 15 minute mile [4mph] for that calculation.)

Which brings me to the next point that the article makes:
"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."
The solution to this problem is a fairly simple, two-pronged approach:
1) If you're trying to lose weight, keep the junk food out of the house. You won't consume an entire bag of Cool Ranch Doritos if you don't buy them in the first place. Yes, keep a couple favorite treats on hand (what's life without treats?!), but buy them in small quantities. Maybe even divide the package up into smaller quantities in plastic bags (or small, reusable containers, if you're eco-minded). You'll be less likely to eat 17 Oreos in one sitting if you've have to go back to the pantry again and again for a baggie with 3 cookies in it.
2) Prepare your post-workout snack or meal before your workout. Make a sandwich or a salad and stick it in the fridge. Cut up some fruit or vegetables. When you come home to that post-workout slump, you can grab your ready-made food instead of junk. And you'll feel better, physically and mentally, for having eaten something healthy after you exercise.

In the end, author Cloud makes the point, "In short, it's what you eat, not how hard you try to work it off, that matters more in losing weight." For all the sensationalism of the headline, the conclusion is pretty much the same thing it's always been: The only surefire way to lose weight is to consume fewer calories than you expend. Exercise has health benefits beyond weight reduction, so the combination of reducing calorie consumption and daily exercise to promote weight loss remains the surest path to success.


  1. Love the new blog! I will be checking in :-)

  2. Ditto! Nice job debunking the article. Now, maybe if I read your blog enough I'll find the time/energy/inspiration to make it to the gym. :)