i started doing ashtanga yoga the hardest one. be careful though, the shits no joke, i hurt my rotator cuff holding one of their wacky positions for too long. you dont even realize cause you hold by breaths instead of reps or counting. but overall for back and hamstrings especially, it was good for me (still using the yoga stretches). generally you should be able to improve alot of your imbalances. cyborg makes his students do yoga twice a week. just look for athletic style yoga and not alot of the breathing and singing stuff.