I started a few months back and I'm 40. Yeah, I wish I'd begun when I was much younger, but hey, I'm working on it now. I'm getting quite a bit fitter and I feel better, but of course there are teenagers in my school that would wipe the floor with me and not break a sweat. But so what? As you get older, you'll learn that age doesn't make a whole lot of difference in a lot of things. I've known kids that were a lot more mature than many adults, and I've known adults I wouldn't let near my two-year-old lest he pick up their infantile behavior.