Role of Sleep in Exercise and Recovery

If you're like most people, your first order every morning is issued by an alarm clock. You awaken remembering that your day is filled with meetings and that the kids have appointments. If you're going to work out today, it's now or not at all. You pull yourself to your feet, hoping that a few slugs of coffee will propel you out the door in one piece. But an inner voice whispers: On five hours of sleep, this isn't worth it. But you get going anyway. So just how important is getting enough sleep to active people?

First, lack of sleep is a two-pronged attack. If you merely think you aren't getting enough rest, you'll carry mental baggage on your run or bike ride or into the gym. Furthermore, sleep deprivation erodes both your mood and your motivation, both of which are required for top physical performance. Oddly, we spend about a third of our lives in dreamland, and after long enough periods without sleep, we literally can't survive. Yet scientists have yet to learn why sleep is a necessity. Nonetheless, researchers have clarified a number of physical processes that can't occur properly without enough Z's, and many of these contribute to peak athletic performance. British researchers, for example, have found that a period of decreased sleep lasting mere days interfered with glucose metabolism and raised levels of cortisol, a stress-related hormone that may inhibit recovery from exercise. This suggests that glycogen synthesis is impaired during periods of reduced sleep, meaning that weary exercisers may head into their workouts with less than a full tank of fuel. Also, levels of human growth hormone (hGH), which is essential for the repair of exercise-induced soft-tissue breakdown, are at their highest levels during undisturbed sleep. Interruption of deep sleep may lead to prolonged recovery from exercise owing to decreased levels of hGH.

Second, many athletes and coaches believe that a consistent sleep pattern is more important than the total amount of time spent sleeping. Regardless, the optimal amount of sleep varies greatly among people. "In order to adapt positively to training, it is necessary to obtain adequate amounts of good quality sleep," says former U.S. Olympian and exercise physiologist Pete Pfitzinger, Ph.D. "The required amount appears to differ markedly between Avoid drinking caffeine, alcohol, and intense exercise for at least six hours before going to bed. Maintain a dark, quiet environment in which to fall asleep. If you take naps, try to take them at the same time each day. And In the last several hours before bedtime, engage in relaxing activities: reading, listening to music, taking a warm bath, a leisurely walk.