I started to enter races this year and have followed a "self administered" training program beginning last fall. Even at our age imporvements in speed and fitness can be made with a training plan and effort. I will say doing those sprints, I mentioned, are not without a little "discomfort". The first several times I did the set it reminded me of the sprint intervals we did on our college track team. I know I gave it maximun effort when at the finish of the interval I don't know weather puke or mess my shorts, then after a couple minutes it all starts again. The rewards on group ride sprints against others' have been worth the suffering. BTW, my 24 yr old son will sometimes do them with me and he can hit 39+ mph on the same sprint.