Antagonist muscle groups, such as biceps and triceps, perform opposite actions. Training them back-to-back, as in supersets, increases the strength and power of the second muscle group trained.
Theoretically, if the antagonist muscle group is fatigued, it doesn’t interfere with the actions of the other group, and strength and power are maximized. New research shows that this works well with leg strength.
Subjects performed the vertical jump on a force plate. They did a six-second isometric leg curl to fatigue the hamstrings, then immediately did a vertical jump; they also did a vertical jump without the leg curl. Doing the leg curl increased quadriceps force production by almost 15%.
For greater lifting strength, perform a 5- or 6-second isometric contraction of the antagonist muscles you are training. For the bench press, try isometric rows; for curls, try isometric pushdowns; for shoulder presses, try isometric pulldowns; and for leg extensions, try isometric leg curls.