Is endurance running bad for you?

Long-distance running stresses the body: recent research from the University of the Peloponnese in Greece found that post-race levels of inflammation in the blood of ultra-endurance runners (those who run races longer than a marathon) showed similar profiles to people with cancer or cirrhosis. However, over the next few days, the runners’ levels returned to normal, suggesting that they have a remarkable ability to recover after an extreme workout. Good training is partly about building an awareness of your limits, so that you know when, for instance, you’ve crossed the line from ‘good pain’ into ‘bad pain’.

Kate Smyth was escorted from the track when she collapsed after running the marathon at the 2006 Commonwealth Games

Marnie Chesterton is the presenter of What Are The Limits Of Human Endurance? – an episode of CrowdScience that can be streamed at bbcworldservice.com/crowdscience