Ok I just got back from my spinning class (it's raining so I didn't ride today) and I have a few questions. During the class we were asked to do these things called jumps, which are kind of like really fast squats on the bike while pedaling. What is the purpose of this move? I never bounce up and down out of the saddle when I ride. On top of that they seem like a knee injury waiting to happen, but that maybe because our counts seem too fast for this to be effective.
Can you all clue me in on what this move is supposed to do and if I am missing out on some fitness benefit by not doing it?