I ride a mountain race here every year for the last 9 years in the road category. It is 13 miles with 3000 feet vertical gain, a real bear of a climb and this year I logged my personal best, 1 hour and 4 minutes. I'm 52 and for the first time this year really wondered if I'm getting too long in the tooth for this sort of thing and have since thought about hanging up racing and just ride for the fun of it. Anyone else ever have these doubts? This race requires basically a maximum heart beat for over one hour, in my case over 170 and lately I'm concerned with doing these efforts at my age, think I'm fretting over nothing or is it time for the rocking chair?