I've always been told that plyometrics are an excellent for of not only toning muscle but increasing "burst" speed for any number of sports (soccer, football, tennis, etc.).
But I've found that most people (and I'm also talking about soccer programs and teams and such) don't really put emphasis on it. In fact most of the people I know tend to just do weights and speed training (treadmill or the like) and do very little if any plyometric exercises.
Now I know that many of the exercises are killer on the knees and ligaments around the knee joints, and that might be a reason not to do them all the time.
So I was wondering who out there does plyometrics, for what purpose, and to what extent are the exercises dangerous and/or useful?
Thanks in advance.