Frerichs raced in Doha two years ago, in a different event, and encountered a frustrating problem: it was too hot to train outside. She and her teammates ended up practicing on treadmills in an air-conditioned gym or running at night to avoid the worst of the heat. This year, she and the other athletes who will race on the track will benefit from a new, air-conditioned stadium. Marathoners, who will run along Doha’s waterfront outside the stadium, won’t get that luxury. Before competing, many athletes will wear ice vests and wrap cold towels around their wrists and neck to bring down their core temperatures.
Danny Mackey, who coaches the Brooks running team, is preparing his runners for Qatar by having them sit in a sauna for 20 minutes after they finish their runs and before they start lifting weights in the gym. “Coaching becomes not just how many miles they’re running or what weightlifting routines they’re doing,” he says. “The conditions are critical.” Because his team trains in typically cool Seattle, Mackey urges runners to wear extra clothing during their workouts, and as the event nears they will move to hotter training locations.
Of course, elite athletes aren’t the only ones affected by heat. Construction and agricultural workers, who spend a lot of time laboring outside, are vulnerable, as are members of the military. Since 2008, at least 17 service members have died from heat exposure during training. Heat stroke is also the third-leading cause of death among high school athletes. What researchers want is a better way to predict who’s at risk, well before a heat stroke strikes. “There are two holy grail items,” says Doug Casa, head of the Korey Stringer Institute at the Unversity of Connecticut, which studies heat’s effect on athletes. “Real-time assessment of core body temperature and hydration.”
But unlike measuring heart rate or step count, there is no wearable device that can gather that data. To get an accurate core temperature reading, Casa says that, essentially, “we need something at the organ level.”
Right now that means using some impractical and unpleasant techniques. A rectal thermometer, for example, gives an accurate core temperature but isn’t welcome during a military operation or a marathon. Some researchers use a swallowable thermometer the size of a multivitamin that can report the temperature around your intestines. But at roughly $50 a pop, they’re too expensive to use regularly.
Mark Buller, a computational physiologist at the United States Army Research Institute of Environmental Medicine, notes that internal readings aren’t fool-proof either. “It’s not necessarily the hottest person who will succumb to a heat injury,” he says. He’s working on an algorithm that can extrapolate core temperature from heart rate and skin temperature, and he’s looking to isolate other predictive factors, such as aspects of a person’s gait.
Hydration plays into the equation too because when we sweat, we lose body mass. “For every additional one percent body mass loss, you’re about half a degree Fahrenheit hotter,” Casa explains.
Even with all the preparations by the facility and by athletes, the teams preparing for Doha still face risks. Athletes compete hard and will often ignore warning signs like dizziness or nausea to finish a race. “The most heat acclimatized, hydrated person in the world can still get too hot if they go too hard and it’s hot enough outside,” says Casa.
Perversely, Epperson says the marathon is already so extreme that dealing with heat feels like less of an issue. “It’s a little easier when you’re training for a marathon,” he says. “Because at a certain point in the race, if you’re not hurting, you’re probably not running the marathon correctly.”.