Thursday, May 31, 2012

“Beware of Exercise” is a Sexy Headline

A new study purports to muddle the health benefits of exercise. I sense that the fat acceptance movement will delight in the findings, but they should pause to consider the details of the study. The New York Times reacted to the study by asking “Can Exercise be Bad for You?” (That headline was later replaced.) I would counter that exercise is good, but the body is unforgiving.

The study reviewed the findings of six other studies, one of which consisted of considerably younger adult subjects. Two other included studies consisted of groups with average body-mass indices in the obese range, whereas all other studies had average body-mass indices in the overweight range.

The paper made its primary conclusion that about 7% of the subjects suffered a worsening of two out of four heart disease risk factors, consisting of fasting insulin, HDL or “good” cholesterol, triglycerides, and systolic blood pressure. However, the included study with younger participants consistently had relatively low rates of adverse reactions. The studies with obese-range body-mass indices suffered adverse reactions more frequently. Eating behavior received no direct examination.

Rather than denigrate the role of exercise in countering the obesity epidemic, as the media response has done, I would conclude that an exercise regimen should begin earlier in life. Rather than bolster the fat acceptance movement, this study should warn against ever becoming obese.

Claude Bouchard, Steven Blair, Timothy Church, Conrad Earnest, James Hagberg, Keijo Häkkinen, Nathan Jenkins, Laura Karavirta, William Kraus, Arthur Leon, DC Rao, Mark Sarzynski, James Skinner, Cris Slentz, & Tuomo Rankinen (2012). Adverse Metabolic Response to Regular Exercise: Is It a Rare or Common Occurrence? PLOS One, 7 (5) : 10.1371/journal.pone.0037887