Runners Show Less Muscle Fatigue After 200 Miles than 100 Miles, Study Says

A new study suggests that after running a 200-mile ultramarathon, fatigue and muscle damage is less than it would be for people who had run only had half the distance, namely because of the slower pace and extra sleep the 200-mile racers require.

Researchers from Switzerland's University of Lausanne conducted a study on the neuromuscular damage done by running an ultramarathon - an endurance race significantly longer than the typical 26.2-mile marathon course.

Seasoned ultramarathoners were given blood tests for inflammation and tested for muscle fatigue before, during and after the Tor des Géants, a 205-mile race in Italy's mountainous Aosta Valley.  According to Runners World, the race is among the most difficult ultramarathons in the world, with 20 mountain passes and a total of 78,000 feet in elevation change.

Some ultramarathons are 50- or 100-mile events where the competitors plow through the course, taking little if any rest. The researchers found that in the longer 200-mile races, the runners' slower pace and regular en route napping actually helped protect the runners' muscles far more than their peers running an equally mountainous but only half-as-long ultramarathon across the French Italian and Swiss Alps.

"It was a surprise it was such a big difference," said Jonas Saugy, a sports physiologist at the University of Lausanne who led the research.

Before, during and after the races, Saugy and his team measured muscle strain in the racers' knees and feet using a custom-built chair with a testing gauge and recorded the electrical activity of their muscles with electrical stimulation. They found that Tor des Géants racers had about 30 percent more strength in their lower leg muscles despite running nearly twice the distance.

A big factor in the 200-mile runners' greater muscle strength had to do with the amount of sleep they got during the race. According to Popular Mechanics, previous studies indicated that sleep deprivation did not have a direct effect on the muscle strength of ultramarathon runners. But Saugy's data suggests that even brief breaks for sleep were important periods of rest for the runners' muscles.

"The addition of sleep" once the runners have built up a sleep deficit "was the reason for the muscle conservation," Saugy said.

Saugy and his colleagues' research is published in the journal PLOS ONE.