WHAT IT IS
A method in which you do two exercises for opposing muscle groups back-to-back without rest. Joe Weider stressed the word opposing to recommend that the two exercises in the superset be opposite motions, like a chest press and row, or a leg extension and a leg curl.
WHAT IT DOES
Training opposing movements allows you to work two distinct muscle groups with less rest. While you’re doing presses, for example, your back muscles rest, and vice versa. You can train the two body parts with the same amount of rest as you’d need in straight sets.
HOW TO USE IT
Instead of training chest with triceps, pair up chest and back. Pick an equal number of exercises for each body part and pair them up. Every other pairing, switch which body part goes first. Don’t rest between exercises and only two minutes between supersets.