Lesions in the legs do not preclude ultra-marathon running for 100 days without pain: case report.

There is an increasing interest in participation in ultra-endurance events and a concomitant need to understand their effects on health. The effects of extremely prolonged running on leg joints, ligaments, tendons and menisci have not been explored sufficiently. The aim of the present single case study was to use ultrasonography to estimate the effects of a self-paced 8-10 hours daily running for 100 days on the morphology of joints in an experienced 47-year-old ultra-marathon runner. Examination before the start of the 100 days of running revealed already multiple but mostly mild, painless lesions in different joints of both legs. The presence of these lesions did not significantly exacerbate or cause pain during the racing. Iliotibial band bursitis and Achilles paratenonitis were however aggravated, and mild semitendinosus bursitis was a novel finding during the examination after running 8000 km in 100 days. These results are impressive because preparation for this 8000 km running was only ~5 weekly hours of training. In conclusion, this runner displayed multiple lesions in the leg joints at the start but was able to increase running volume by ~10-fold for >100 consecutive days without significantly exacerbating the pre-existing skeletomuscular abnormalities or inducing pain.