Well, I don't know about being held back so much as just getting to be less flexible and enjoying more pain as I get older and/or exercise less... I certainly don't recover as quickly as I did in my 20's or even 30's, but I find that if I stay away from the gym, EVERYTHING gets harder to do. I've been going to the gym steadily again for the past 6 months, and I feel immensely better (in terms of strength and flexibility) than I did back in May. I am nowhere near as flexible as I want to be (especially after learning that flexibility is important to longevity... lol), and so I am actually consider a Yoga-type class to supplement the jujitsu/kick boxing stuff. I just have to get over my shyness/chickenness of wading into a class full of women on mats.