Turning Down the Heat - Page 2
"It's as if you were training at altitude," says Karen Harvey, assistant coach of Florida State University's division-one women's cross-country team.
Humidity compounds heat's effects on your performance level, making evaporative cooling (when sweat evaporates and cools the body) less efficient because evaporation cannot occur quickly enough to dissipate excess body heat. Consequently, the outside temperature feels even hotter than it actually is. And while heavy sweating is a sign of a healthy thermoregulatory system, losing large amounts of water increases your risk of dehydration, a major contributor to heat illness among runners.
Replace What You Lose
Create a hydration schedule to replace the water and electrolytes lost through sweating while running. "I drink one to two 20-ounce bottles of water or electrolyte drink like nuun (www.nuun.com) an hour, taking small sips every two minutes," says Lisa Smith-Batchen, coach and two-time winner of the 135-mile Badwater Ultramarathon in Death Valley, California. "And if it gets really hot, I take two or three Endurolyte capsules (www.hammernutrition.com) or one SaltStick (www.SaltStick.com) an hour on top of that."
Smith-Batchen warns that heat can render your favorite food and drinks unappetizing, so train your stomach to tolerate fuel with hot-weather training runs. And if stomach cramps or nausea set in, slow your pace and up your electrolyte and water intake.
While it is possible to adapt to hot climes (after about eight days the thermoregulatory system increases sweat production), no amount of acclimation, e.g. training in a sauna or under heavy clothing layers, will make you immune to heat's energy-sapping effects.
The best line of defense is avoidance. Harvey plans her team's workouts to miss the hottest time of day, when the mercury often hits the 90s. "We do tempo work or intervals in the morning or on trails under the trees," she says.
If they must train in extreme heat, her athletes reduce the workout intensity (staying well below their maximum heart rates), without compromising the workout's quality since running slower in hot weather produces the same fitness gains as running faster in cool conditions. Your body composition, age, mental toughness and general conditioning all play a role in how much you should reduce running intensity, though Lillegard suggests a minimum 25-percent reduction. "If you're running at a perceived exertion of moderately hard, meaning you can carry on a conversation, then you're in a safe heart-rate zone," he says.