In the 1995 eco-challenge, adventure racer Robyn Benincasa and her teammates decided to complete the seven-day, 300-mile course without wasting time on sleep. "That," she now admits, "was a bad idea." By day three, during a 75-mile hike through the Utah backcountry, they’d turned into a stumbling pack of zombies. "We spent seven hours wandering in circles," the 41-year-old recalls. "And then all five of us passed out in the dirt."
There’s no way to cheat sleep: The longest a human has ever stayed awake under supervised conditions is 11 days. After just 16 hours awake, the brain centers that control attention, visual processing, higher reasoning, decision-making, and memory start to flicker on and off—the mental equivalent of a transmission popping into neutral without warning. Going 22 hours without sleep is like knocking back four shots of liquor: Reaction time dips 57 percent; hand-eye coordination, 31 percent; and memory, 10 percent. And after three days, as Benincasa learned, you’re facedown in the dirt.
Researchers are still in the dark about why we spend a third of our lives unconscious. Theories about sleep’s purpose range from memory consolidation to emotional processing to—as experts recently discovered—physical performance. For all the talk of HGH and steroids, sleep may be the best (and safest) athletic enhancer available. You just have to know how to use it. So read on, rest up, and conquer.