The Time Magazine Exercise Debate - Why Exercise Won't Make You Thin.

by Mark Doering, CSCS

Many of you may have seen the recent article in TIME titled, "Why Exercise Won't Make You Thin." If you haven't, take a few minutes to read through it as the title alone implies that exercise is useless in the battle of the bulge. Perhaps you are now questioning why the hell you are exhausting yourself exercising. In my quest for the truth I went to the source itself, the actual research article, to make some sense of this exercise debate.

The original research Time Magazine refers to is a study by Timothy Church et al. (2009) titled, “Changes in Weight, Waist Circumference and Compensatory Responses with Different Doses of Exercise among Sedentary, Overweight Postmenopausal Women.” If you are not up for reading it yourself I"ll do my best to save you the time and sum it up in a few concise points:

1. The Church et al. research states that “The goal of this analysis was to examine actual weight loss compared to predicted weight loss across different doses of exercise in a controlled trial of sedentary, overweight or obese postmenopausal women.” The research results state that, “we observed no difference in the actual and predicted weight loss” in two of the three exercise groups, and observed half the predicted weight loss in the third exercise group. To restate this, all three exercise groups lost weight, but only two of the three groups lost as much as the researchers expected them to lose.

2. The Church et al. research states that "all exercise groups had a significant reduction in waist circumference which was independent of changes in weight.” Again, let me rephrase this - everyone who exercised saw their waist get thinner despite how much weight they actually lost. The Church et al. research goes on to state, "Excess abdominal obesity is associated with increased risk of mortality, CVD, diabetes, insulin resistance and metabolic syndrome. These findings reinforce the positive health benefits of engaging in physical activity even in the absence of substantial weight loss."

3. The Time article is claiming that by exercising you end up a) eating more overall calories and b) eating more unhealty foods due to decreased self control. The Church et al. research states that "our measures of food intake, a food frequency questionnaire, is not optimal to measure small changes in energy intake. Further the study could have benefitted from a more rigorous and sensitive measure of energy intake. The food frequency questionnaire utilized in DREW prevented us from being able to definitively demonstrate that the observed compensation is the result of an increase in energy intake." In other words, they didn't accurately record the participants caloric intake well enough to make any conclusions of how this effected their results.

My conclusions from this research article:

All three exercise groups led to weight loss and waist reduction therefore contributing to make these women thinner. Of course if you are not a sedentary, overweight or obese postmenopausal woman with elevated blood pressure than I can't say if your results will necessarily be the same. Which is a limitation that Church et al. state, "we do not know if the results will apply to other women or men."

While this is my very basic explanation of this research I would encourage you to check out these other rebuttals to Time's article for more detail:

TIME's Great Exercise Debate: What's In It for You?
by Spark People

or

Is Exercise a Waste of Time? Why Time magazine is wrong about working out.
by MSN

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