Feasting is one of the major activities of the holiday season. But, if you’re one of those people who’s concerned about yuletide nog going straight to your gluteus maximus, the world of science has an exercise tip. That is, a new study suggests that morning exercise might be the most effective way of warding off weight gain (and diabetes).
The study, which appeared earlier this month in The Journal of Physiology, recruited 28 men at the Research Centre for Exercise and Health in Belgium.
Over the course of six weeks, scientists fed these subjects almost exclusively on junk food – a diet composed of 50% fat. Then they instructed a few of the participants not to exercise at all. The rest exercised strenuously four times a week. But these get-in-shape guys were divided into two different groups: one was offered a big breakfast before exercising. The other group was asked to exercise in a fasting state – in other words, first thing in the morning, before breakfast. The New York Times succinctly reported the results:
Only the group that exercised before breakfast gained almost no weight and showed no signs of insulin resistance. They also burned the fat they were taking in more efficiently. “Our current data,” the study’s authors wrote, “indicate that exercise training in the fasted state is more effective than exercise in the carbohydrate-fed state to stimulate glucose tolerance despite a hypercaloric high-fat diet.”
Insulin resistance, by the way, is just the body’s inability to effectively pull sugar out of the bloodstream to nourish its muscles.
The scientists who conducted this study still aren’t sure why exercising before breakfast causes the body to burn a relatively greater percentage of fat. It may enhance oxidate fatty acid turnover, they say. Hmm.
Many commenters at the NY Times site noted that the study was small, and that it just involved subjects of the male persuasion. Both counts are worth considering. Follow-up research is certainly required but, in the meantime, exercising just after you wake up might be worth trying out … if you can stomach it.
Beth Lebwohl researches, writes and helps produce science content in audio and video formats for EarthSky. She is one of the authors on EarthSky.org, a script-writer for our podcasts, and helps host our English science podcasts in 90-second, 8-minute and 22-minute formats. Beth came to EarthSky in 2006 from the American Museum of Natural History's Department of Astrophysics, where she was surrounded by some of the greatest telescope-building, equation-wielding, code-writing physicists of our time. And they made her think . . . this science thing . . . it's pretty cool.