A question for anyone familiar with P90

[Guest guest]

I'm currently 2 weeks into P90, 1-2. I'm getting better at the cardio, but my thighs are still fatiguing on me. I suspect this will get better and improve over time, as it has so far. But my question is this...

I'm now up to 5lb weights on Sculpt 1-2 and think I'm ready to move on to 8lb weights. I'll alternate between the 5s and 8s before moving to 8s alone, but 8 is the heaviest weight I own. Once I master 8lb repetitions, would it be good to move onto Sculpt 3-4? Just how much harder and different is 3-4?

PS - if you have any suggestions about the thigh fatigue, please let me know.

PPS - it's not helping that I saw P90 on sale on Craig'slist.com for $15!!!

-Terri-