While recovering from the 1st set of exercise A, you can do the 1st set of exercise B (working an entirely different muscle group), before going back to do the 2nd set of exercise A, etc.
This is known as 'supersetting' and is an entirely legitimate training technique.
I agree with the other posters - if you can do 20 reps, it is time to move up to a heavier weight/more challenging exercise. If you can do 20 reps, it is no longer challenging enough to be effective ST. One way to make things more challenging is to slow things down - 3 seconds for the up movement, and 3 seconds for the down. That way it is your muscles doing all the work, not 'bounce' or momentum.
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.
| current weight: 178.0