The P90X chest and back workout consists of a set of exercises which are done in two sets... do each exercise (pushups, pullups, rows, etc) for X seconds (varies for each exercise), and then repeat the whole thing again. It takes about an hour to complete.
I don't have a full hour to devote to the program, but I will be able to do just the "first half" each night. I remember reading that 80% of the muscle mass gain is acquired from the first set, and that repeated sets are mostly done to improve tone. So, my questions are:
- Is this true?
- Based on the answer to the first question, is it worth it to complete only half the prescribed regimen?