Not too old. I've just started at 35, 8 months after having a baby. I started taking my 4 year old to a Karate lesson and it looked so much fun thought I should have a try myself. One evening a week I do an hour or circuit and core body strenght exercise with them, followed by hour and a half or Karate plus 30 mins of self defence. It's great fun After Christmas when I'm a bit fitter will add in another session.