TEN YEARS AGO, a Stanford researcher named Cheri Mah, examining how sleep patterns affect students' brains, came across something unexpected. Some of her test subjects happened to be Stanford swimmers, and they told Mah they set personal bests during the part of the experiment when they slept more than usual. Mah knew that many studies had reported how sleep deprivation can lead to declines in physical performance, and she wondered if those findings could be inverted: Does extra sleep boost athletic achievement?
Some of our genes act as internal clocks and release hormones according to cycles called circadian rhythms, which are triggered by darkness and light and alternate over 24-hour periods. When we mess with these rhythms by not getting enough sleep, our metabolism of glucose (which gives us energy) declines, and our level of cortisol (which causes stress) increases. Further, sleeping for long stretches is naturally anabolic: During deep sleep, our bodies release growth hormone, which stimulates the healing and growth of muscle and bone. So while it's possible to push through a lack of sleep during any one day, proper sleep helps athletes in two ways. First, it boosts areas of performance that require top-notch cognitive function, like reaction time and hand-eye coordination. Second, it aids recovery from tough games and workouts.
The U.S. Olympic Committee began taking the issue of adequate sleep seriously in 2005, when it consulted with sleep specialist Mark Rosekind, a former NASA scientist, to help redo rooms at the Olympic Training Center in Colorado Springs and at the 2006 Torino Olympics. Out went twin beds; in came plush-top mattresses, blackout curtains, thermostats set to cool temperatures and reliable alarm clocks. Rosekind and his colleagues pushed for the Olympians to get nine to 10 hours of sleep a night, not the five to seven most young adults manage. "People need to be as smart about sleep," Rosekind once said, "as they are about diet and exercise."
Performance consultants and technology firms agree. Athletes' Performance, a leader in developing training and nutrition regimens for pros and Olympians, announced in February that it will use products from Zeo, a leading sleep-management firm, in its programs. Zeo makes devices such as a Bluetooth-enabled headband that tracks your brain waves while you're asleep, reports your patterns in great detail and summarizes your overall sleep quality in a ZQ Score. "We're already seeing them say, 'I got nine hours last night, what was your ZQ?'" says Mark Verstegen, president of Athletes' Performance. He calls sleep a magic pill.
Tony Dungy and my wife like to say that nothing good happens after midnight. It turns out they're wrong, but you have to be in bed -- and sleeping! -- to realize it.