Outside magazine, March 1999
Drop and Give Me ... a Nap
Why hitting the sheets may be better than hitting the streets
By Peter Lewis
In our endless quest to stay fit and healthy, suddenly we find out that the time-crunched athlete is doing more harm than good by setting the alarm early to squeeze in a predawn workout. In a study that has just been completed but not yet published, researchers at the University of Chicago's endocrine rhythms laboratory discovered that, rather than merely making folks groggy and uncoordinated, skimping on sleep triggers a decrease in human growth hormone, which controls the body's ratio of fat to muscle. If HGH dips below its proper level, muscles wither and fat builds up, negating many of the positive effects of exercise. Thus trading shut-eye for a workout, says Eve Van Cauter, the chair of the university's endocrinology department, who oversaw the study, "is totally counterproductive."
Accordingly, it's crucial for athletes to get a full eight hours of sleep. Forget what you've heard about people needing vastly different amounts of snooze time, ranging from six to 10 hours, says Brown University chronobiologist Mary Carskadon: "You can fit the variations among virtually all adults in about an hour's span." And, she allows, you can use a nap to reach that eight-hour goal. Short ones (30 to 45 minutes) are the most restorative; any longer and "sleep inertia kicks in," explains Carskadon, "making it harder to wake up." Thus armed, you'll have the sharp wits of the well rested and the muscle tone to put those wits to use.
Illustration by Jason Schneider