Clarifying “The Myth About Exercise”

10 08 2009

TIME Cover_myth about exercise Every Saturday I look forward to the TIME magazine in my mail. I know I can read it all online, but there is something satisfying about print media. As someone trained in sport science (aka, Kinesiology) this week’s cover story by John Cloud “The Myth About Exercise” intrigued me. After reading it, I was more than surprised, a bit irritated, and wondered if this wasn’t just more sensationalistic journalism. The premise of the article was based on “some recent studies” that found exercise does not help one lose weight or isn’t as important as we’ve been led to believe.

What?! Have we been lied to all these years? A friend who regularly works out read the article and promptly said, “THAT was depressing and made me never want to work out again.” I wondered how many others were thinking similar thoughts.

The TIME article, based in part on the findings of ONE clinical trial, found that in a group of 464 overweight women assigned to four conditions—women who exercised did not lose significantly more weight than those who did not exercise…and some women in each of the four conditions gained weight.

Dr. Timothy Church, Chair of Health Wisdom at LSU and lead author of the clinical trial, outlines the process of exactly how exercise might psychologically work against us:
1. exercise stimulates hunger
2. when we exercise we often “reward” ourselves with food [see my blog post about this issue in youth sport]
…or both. My astute friend mentioned previously, pointed out this premise assumes that those who don’t exercise don’t reward themselves with food.

Cloud offers an additional explanation based on another study with UK children he’d written about earlier this year
3. One might be more sedentary during non-exercise times than if one didn’t exercise at all

At first read, these findings and the TIME article may be perceived as a green light to bolster couch potato status, and only pay attention to what you eat–and this is dangerous. Exercise matters…but more importantly researchers have demonstrated movement matters!

Weight management is a simple energy equation: energy in (food) < energy out (exercise + energy expended daily to move about, live, & breathe) = maintain or lose weight.

If you take in more than you expend, you gain weight. Given that our metabolism slows 10% every decade (i.e., meaning you burn 10% less calories/energy), even if you ate exactly the same as you did as a teenager…you’d gain weight. True, exercise is only HALF of the equation, but a still needed half.

With billions of dollars tied up in the health and diet industry and new products and advice generated daily, I’ve joked for years that I’m going to write a one-page best seller—Move More, Eat in Moderation (© 2009 nmlavoi). Alas, I fear this would not be a best-seller nor make me enough money to become a full time blogger….Americans want the easy route, the quick fix, and watching what you eat and factoring movement into one’s daily plan takes a bit of effort.

TAKE HOME: The research cited in the TIME article is mostly one-sided, although it does raise some interesting questions. Many other researchers have found that exercise/movement IS important, can lead to a host of positive outcomes, and can provide a buffer to chronic diseases associated with obesity. This is a perfect example of why a critical perspective can be valuable….so…off the couch!

To promote healthy eating, and active living in a society in which obesity rates continue to grow, attention to both is critical. This well-placed article in a well known weekly magazine may do more fan the flame of weight loss mythology, than help.

p.s. The tired gendered cliché of “woman running for something sweet” on the cover did not escape notice

UPDATE 8/10/2009: To prove my point about sensationalist health journalism, today a University of Minnesota colleague Gary Schwitzer, a longtime health journalist “sounded the alarm this week after analyzing hundreds of medical news reports from the past three years” in an article in The New York Post.

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