I used to get terrible pain in both shoulders, and in the area of the sciatic nerves (i.e. a terrible pain in the arse and upper leg). It used to last days after a decent cycle ride, and when I was commuting the 17 miles each way trip to work and back in the summer, it was a permanent fixture.
Doctors suggested changing riding position. Didn't work. They suggested changing bike and wearing padded shorts. Still no better. In fact I'd all but given up on ever getting rid of it and was accepting limping about like I'd been run over by a truck and moaning like a geriatric as part of not being in my twenties anymore, when my wife (an accountant with a sideline in teaching yoga) suggested a couple of basic yoga poses.
Fixed it in about 20 minutes flat, and it's not been a problem since... :shock:
Of course you'd think that my lifelong suspicion of yoga and all the hippy, joss stick burning spiritual mumbo jumbo that goes with it would have been immediately dispelled and yoga adopted as part of my everyday routine...
Nope, not a bit of it. Still regard chanting, and "purging the third eye" as a little bit off the wall, but some of the stretch exercises are really bloody good...