46 now I started my present Aikido practice when I was 31 I echo the comments about stretching. My Sensei is a certified Yoga Instructor too. I have been trying to slide on it but if I don't keep stretching I have a terrible time blending and have to use too much strenght.
We had a guy get his Shodan at 70. His can't move like a man in his 30's or 40's but his Martial Spirit is huge.