According to the old Chinese proverb, a long journey begins with a single step. But for Running the Sahara team members Charlie Engle, Ray Zahab, and Kevin Lin, it began in a lab. Read on for a look at how these athletes' bodies coped during this historic run.
To figure out the optimal game plan, Charlie approached the Gatorade Sports Science Institute (GSSI) in Barrington, Illinois, and asked for help.
"His biggest fear was dehydration," said Beth Stover, one of the lab's scientists, who noted that on previous desert runs, Charlie had had problems with hallucinations and dizziness.
Stover and her colleagues put the runners on treadmills in a room heated to 117°F (47°C) —mimicking the temperatures in which they were expecting to run. There were even heat lamps to simulate sunlight.
There, the three ran at their expected effort level while the scientists measured the rate at which they sweated.
"We also measured their sweat's electrolyte concentration," Stover said, "because depletion of sodium, the primary electrolyte in sweat, can lead to muscle cramping."
Gatorade then gave the team a mountain of powdered sports drink, which each runner was to consume according to an individual plan, ranging from one quart (0.9 liters) to 1.5 quarts (1.4 liters) per hour.
The scientists also measured the runners' oxygen usage, an indicator of how many calories they would be burning per mile. The tests indicated they would need between 6,000 and 9,000 calories per day—three to four times the intake of the average American.
Eating so much might sound like a treat, but it's actually a chore. "When I see that amount of food, I think, 'My gosh,'" said Stover's colleague, Kris Osterberg.
Once the run started, Stover and another colleague went with the team to Africa to monitor the runners for the first few days. "Our goal was to see if we'd accurately measured their sweat rates in the lab," she said.
Another scientist had the runners swallow a vitamin-sized capsule containing a radio-transponder that monitored their body temperature. The runners' temperatures stayed within a degree or two of normal, which meant the hydration plan was working, since runners who get dehydrated will quickly begin to overheat.
Most people can't imagine running a 40-mile (64-kilometer) day in perfect conditions, let alone in a desert. But to cross the Sahara, these runners had to accomplish this feat daily for nearly four months.
During that time, a lot of things can happen to your body.
Initially, it adapts. You sweat more (for more efficient cooling), and your sweat becomes less salty in order to conserve sodium. Needless to say, the runners had trained in heat, so these changes had largely occurred before the GSSI scientists conducted their treadmill tests.
You also become increasingly fit, and your body may adjust its metabolism to burn fewer carbohydrates and more fat. Ray says that before starting, he'd bulked up from his normal 150 pounds (68 kilograms) to 161 (73 kilograms), but by the end of the run he was down to 132 (60 kilograms).
Then there are the inevitable aches and pains. "I like to say that this type of running is 90 percent mental, and the other part is all in your head," Ray jokes. "They told us that after a certain amount of time your body's going to adapt or fall apart."
Even so, Ray said, there were times when his body tried to pack it in. "I had horrendous tendonitis," he said. "You just have to will yourself past that point. The injuries go away after a while."
Part of what kept Ray and the others going was the medical team that accompanied them all the way across the desert. But they also experienced something conventional sports medicine is only now discovering: Under some circumstances, the body will heal itself while continuing to be active.
What happens, doctors are learning, is that activity actually becomes helpful to the recovery, especially from relatively recent injuries. The body adjusts to relieve stress—especially for trained athletes like the Running the Sahara team.
For example, a runner with a sore knee will alter his stride to absorb more of the impact in his calf. If the knee recovers before the calf starts to hurt, he's managed to heal without having to stop.
Not that the runners were thinking so theoretically. "If I was at home, I would have stopped," Ray says. "Every day I had a choice. I sort of forced myself into an adaptive phase."
Screenings and Events
People and Places
Champion Athletic Apparel