If you want to burn yourself out at 80 (and I doubt I'd get to that age if I took the 'burn out' path!
)then they're giving you a way to do it!
I would consider dying at 80 as burning out to a premature death since my parents got to 84 and 86 without much exercise in later life or a 100% healthy diet, and many other members of my family got to 90, 95 or even 100+!
I'd like to think that in 25 years time I will have about the level of fitness that I have now. I intend to significantly improve my fitness over the next couple of years, but then, as ageing really begin to take hold, slowly slip back to my current level and (hopefully) burn out before I drop much below that.
Join me on a slow, hilly 60 mile forum ride in 2037?
The research looks at possible consequences of over training (something I suspect that most of us here, myself included, do not get anywhere near). The report's conclusion makes suggestions for preventing damage, they do not recommend against the exercise.
The point that I was making with the Tour de France rider survey was that it came to the opposite conclusion. I'm sure that many of those riders pushed themselves to the point of overtraining and they certainly did
not get adequate recovery on their Tours!