For a growing breed of runners, marathon distances just don’t cut it anymore, with ultrarunners seeking distances that go far beyond the 42-kilometre mark. While bruised toes and muscle strains are part of the package, a new Stanford University study finds that ultrarunners are a lot healthier than the rest of us.

In findings published Wednesday in the journal PLOS One, researchers looked at 1,212 ultramarathoners, mostly men in their early 40s, as part of its ongoing Ultramarathoner Longitudinal Tracking Study. Most runners averaged around 103 kilometres a week.

Results showed that among the runners, 77 per cent reported exercise-related injuries, with 64 per cent of the runners saying that the injury cost them training days; the younger, less experienced runners were the most affected.

Still, they showed up for work or school more than the average American, with participants reporting an average of 2.2 days off a year due to injury or illness. Employed Americans on average take 3.7 sick days a year.

While the runners reported higher than average rates of allergies and asthma compared to the general population, the scientists said this could be due to the drying of the airways during exercise and increased exposure to outdoor allergens.

Perhaps not surprisingly, the ultrarunners had lower than average rates of cancer, heart disease, and diabetes.

According to UltraRunning magazine, 15,500 people completed ultramarathon races in 1998 with 63,530 doing so in 2012.