In reply to krabi123:
You could try supplementing glycine (as from memory I think about a third of your tendons are made of glycine), don't expect any miracles though, as has been mentioned, tendons are avascular tissue and adapt very slowly*, so you'll need to take it for a long time, and the only thing you might notice is not having a connective tissue injury over that period, which may or may not be down to the glycine.
Glucosamine wont help your tendons by the way, glucosamine works with a different type of collagen to the type in your tendons.
If you take Cissus, good luck, because it reaallly tastes foul, and I mean foul. It's also an analgesic, which is worth remembering.
*Throwing in a week of rest every so often might be the best thing for you tendons/connective tissue.