That is a good question. I am 46 and currently a 1st dan. The Grandmaster for our school still practices and teaches and he is in his late 70's. We have a few students that have started in their 60's. There are a few things they cannot do but they have fun and work hard at what they can, its great to see. Of course we are a traditional non contact school so that may be part of the difference. Be well, do your best! Meet great people and have fun. Personally when I cant do it anymore I will probably go back to Tai Chi, I studied for 3 years and really enjoyed it.