About 2 months ago both my lower biceps started hurting whenever I used them to "curl" or pick things up. Also, the tendons in my left forearm were extremely sore. I workout 6 to 7 days a week and have been doing so for 15 years. I am 34 years old and consider myself to be in good shape. I have experienced sore muscles many times but this was more of a pain than soreness. The pain is worse when I rotated my wrists and "curl". I figued that I just pulled something but it has been months and the pain is still there. I have backed off on the weight and frequency of use and went to my doctor. He feels it is just tendonitus and told me to lay off for awhile. The thing I find strange is that it is BOTH arms. Typically an muscle injury would be just one arm not both. Then a few days ago I started getting the same tightness and pain in BOTH my hamstrings near the back of the knee. I went for a run a couple of days before that but I always go for runs with no problems. My doctor ran numerous blood tests for autoimune disorders and lyme and everything came back fine. I guess I could be over doing it, but I have been active my whole life, why now and why both arms and now my legs? Any thoughts?