Exercises that target antagonistic muscle groups cause reciprocal inhibition by moving the same joint in opposite directions. Reciprocal inhibition forces one muscle group to relax while the other contracts. Contraction-inhibiting cellular waste builds up inside your muscles with each repetition during resistance exercise. Alternating between exercise sets that target antagonistic muscle groups back-to-back can help remove accumulating waste, which helps you complete the same number of repetitions for every set and avoid premature muscle failure.
Torso
Exercises that work the front and back of your torso target antagonistic muscle groups. Pushing against a horizontal load with push-ups and variations of the bench press works your pectoral muscles by abducting your shoulder blades, which spreads the scapula away from your spine. Exercises that involve pulling loads across a horizontal path, including chest-supported rows and dumbbell rows, target muscles throughout your back by adducting the scapula. Scapula adductions pull your shoulder blades in toward your spine.
Upper Arms
Flexing and extending your elbows targets antagonistic muscle groups in your upper arms. Flexing your elbow brings your forearm toward your upper arm. Arm curl and pull-up exercises maximize biceps muscle activation by flexing your elbows against resistance. Elbow extension movements straighten your arms by activating the triceps on the back of your upper arm. Tricep extensions and dips involve straightening your arms against resistance and are among the best exercises for your triceps.
Thighs
Antagonistic muscle exercises that work the front and back of your thighs move your knees in opposite directions. Your quadriceps respond to knee extension movements that straighten your legs and include leg extensions, squats, lunges and leg presses. Flexing your knees brings your calves toward your buttocks and activates the hamstring muscles that form the back of your thighs. Leg curls and glute-ham raises are examples of knee flexion exercises for the hamstrings.
Midsection
Abdominal and lower back muscles respond to antagonistic exercises that move your spine and hips in opposite directions. Exercises that flex your spine, including crunches, target the rectus abdominis muscle. Spinal extension exercises, such as lumbar extensions and back hyperextensions, target the erector spinae muscle in your lower back. Hanging and lying leg raises are hip flexion exercises that target the rectus abdominis. Deadlifts and good mornings are hip extension exercises that activate lower back muscles.