A: The numbers to the right of the sets make up the rep range you should achieve on each set. For example, if it says 2 x 7-9, you should do two sets and get seven to nine full reps on each set. You should only do X Reps on the last set (set number 2 in this case), and you’ll probably only be able to get about four to six of those power partials. You should rest about 2 to 3 minutes between compound (midrange) exercise sets. New studies suggest that three minutes is about right for most compound exercises in order for the muscle to once again generate maximum force output. You’ll probably do best with about two minutes of rest on isolation moves, depending on your conditioning.
The () around a number is the drop set rep range, which is usually included on isolation exercises like concentration curls. For example, if it says 2 x 7(5), on each set you should get about seven reps on the first set, reduce the poundage enough so that you get five more reps without rest. Now you rest for about 2 minutes and do it again. That’s two drop sets.