I am 45 years old guy who have been training and competeing my whole life, running, biking and cross country skiing. For
the last 10 years I have been exersicing 3-5 times a week
the last 2 years, however, I have had a serious problem: my thigh muscles are chronically stiff and sore. In particular, the rectus femoris and vastus lateralis are sore. It feels as if I have just fininshed a hard session with uphill running, even when I just climb a few stairs.