I learned a little Wudang martial arts from my grandfather when I was a child. Personally, I think Wushu is practiced since childhood. Most of the apprentices who began to learn martial arts from my grandfather at the age of 20 should be stiff and inflexible. But for the general public, practicing martial arts is to keep fit, and it is not a problem to start learning martial arts when you are old! In fact, you can now find a martial arts master around you, learn some basic routines, and practice several times in the morning and evening or on weekends. If you are lucky, you can find a master with better skills and practice for several years every day, which should yield something. Don't go to those martial arts schools to study!