Two months into her grueling 2007 Arctic expedition, well past the point a normal person would have collapsed in tears, Rosie Stancer was still gung ho. The British adventurer, now 49, was hauling sleds that bore almost twice her body weight in an attempt to become the first woman to travel solo to the North Pole. Temperatures were dipping to minus 60°F, she’d lost two toes to frostbite, and the 478-mile route was littered with boulder-size ice chunks and gaps of open water. “I had a few tearful hissy fits,” Stancer admits. “What kept me going was my fool’s optimism.”
Every athlete has experienced good days, when their legs seem supercharged, and bad days, when every turn of the pedals feels like pushing an anvil uphill. Increasingly, science suggests these variations aren’t just random. In a 2007 study at the London Marathon, for instance, runners suffering from similar amounts of fatigue turned in a wide range of finishes. Those who faltered were often demoralized before the event, while those who excelled were optimistic. The ever upbeat Stancer came within 102 miles of her goal, despite some of the worst Arctic conditions on record. Lucky for most of us, a preposterously sunny disposition isn’t a prerequisite for athletic success. Doctors have ID’d specific strategies we can adopt—before, during, and after an event—to harness the power of a good mood.