I do them as well, they work very well.
To help clarify to people who don't understand what plyometrics are.
They are a type of aerobic gymnastics that involve change in motion at a rapid rate, while concentrating on specific muscle groups.
IE....
Jumping on progressively higher boxes in specific increments of jumps. These can help build your quads.
Running diagonally in front of then behind a series of cones and then back again for a specific time. These help build agility and overall flexibility of the legs.
I hope this helps anyone out there going ????