I have been using these banda along with the P90x system, and they are okay but far too weak for intense workout like those. I agree with what other have said these bands are great for those who are doing much more therapeutic workouts. I own a yellow, red, and green band. I have never used the yellow band because it is far to light for me, The red band I ripped in half after the first three weeks, The green (which is suppose to be the tough band) is still far too light for me. One other thing about these bands you may want to consider is when you hold the bands you're holding to band not a nice padded handle, which after a while really hurts and for me caused blisters on my hands. These are good bands for somethings but a poor choice for other.
Rating: [3 of 5 Stars!]