” Our major finding is that repeated very intense exercise prolongs life span in well trained practitioners. Our findings underpin the importance of exercising without the fear that becoming exhausted might be bad for one’s health.”
These are the findings from a University in Spain studying Tour de France riders. Stop using the excuse that you’ll do to much. The best thing to do is start SOMETHING and refine it as days go by.
See also Wired’s article on this.