Is too much exercise bad for you?

[Bosie]

I found this study today- relating the amount of jogging people did over a 10 year period to mortality.
There is a correlation between exercise and longevity, but this correlation seems to get more tenuous and possibly even absent as the amount of exercise increases.

http://www.ncbi.nlm.nih.gov/pubmed/25660917

Following on from Stig's post of last year about Atrial Fibrillation, maybe doing too much is bad for you?

[sailor]

I see at least two major flaws in this study. Firstly, it deals with jogging, not cycling. Need I say more? Secondly, most of the researchers appear to be MDs, Again, need I say more?