Cycling UK Forum

Just came across this article and as I'm starting to think about challenges for next year, it's prompted to think, at what point does endurance become an unhealthy activity, when do you know? How far is too far?

https://theconversation.com/from-diarrhoea-to-heart-damage-ultra-endurance-sports-put-a-huge-strain-on-the-body-79375?utm_campaign=Echobox&utm_medium=Social&utm_source=Facebook#link_time=1504022451

The research was published some time ago, I recall a doctor being interviewed about it who was pushed to give examples of 'enough' and too much. Eventually, he gave in and said "if you run two marathons a year that's probably OK, if you run six that's undoubtedly too much".

I thought it a daft answer because you might be training a huge amount to do two marathons a year. There again he also said that a brisk 30 minute walk three times a week was all that was needed to keep your cardio vascular system in very good shape.

Surely, it's not just about volume but also intensity. The linked article referenced races and challenges.