I have now done the Plyometrics routine I think 5 or 6 times and let me tell you it gets easier. The first couple times I did this routine I was struggling and almost feeling sick towards the end of the routine, like Tony Horton says this is the mother of all routines in the P90X program. Now that I have done it about a half dozen times I am doing much better. I still am drenched in sweat when I am done and I burn a ton of calories but I can handle it much better so I am sure my endurance has improved over the last month and a half.
My best advice for this routine is to not over do it, if you are feeling like you are gonna cross that point and the workout is becoming so hard you are completely out of gas tone it down a notch for a couple exercises then crank it back up when you feel ready. If you go too far too soon you will burn out and not complete it and you might even lose a little motivation. Push yourself hard but make sure you are able to go on, you will be better off for it in the long run. Tony says don’t try to be hero right away and he is right. I give it everything I got during this routine but I make sure I keep myself in check, if I am feeling dizzy (which I do during this routine sometimes) I slow it down a little. I am not saying dog it, just make sure you don’t go too far and have to quit before you are done. This workout is very hard, Tony says it is the mother of all workouts in the program, so be smart about it.

