<p>Age slow-down for many, and I'd debate most here, is misguided. Assuming otherwise good health, your mileage all depends on how long you've been at this stuff.</p>
<p> </p>
<p>The truth is that regardless of what age you are when you start to hit it hard (words chosen very carefully), you have 5 to 10 years to improve. I stress "hit it hard" to point out when you, as an athlete, transition from "exercising" to "racing" for perfomance. From that point on you have, regardless of age, 5 to 10 years to improve. Most will say 5 to 7 years, but I've found that many -- the true students of the sport and self -- can get 10 years out of it. After that time you start to slow down. Note that age here is all relative. And that's the point. There is no single age where you start slowing down as it pertains to performance. You may see more gray hairs or other signs of aging, but that has little bearing on performance and what you can do depending on when you have started at this higher level.</p>
<p> </p>
<p>This of course is not gospel, and there are variations to it, but it is the general rule I have witnessed in others and have picked up from experts of all sorts. Maybe I picked up the wrong message, but that's the one I got.</p>
<p> </p>
<p>If this is more a question for you in when can you expect to start slowing down, I can give a guess but would need far more information, such as "slow down in what?", when you started being active, when you started these activities, when you started racing (not just exercising), for how long have you been racing, etc.</p>