Virtually every muscle in your body has an opposing muscle that is performing the opposite movement. While one muscle is contracting, the opposing muscle is lengthening. Training opposing muscle groups equally is what keeps your body balanced.

Unfortunately, the muscles on the front of your body, like your biceps or quadriceps, receive the most exercise through daily living and often in the gym, while those opposing muscles on the back (triceps and hamstrings) receive little training leading to imbalances and eventually injury and pain. Another example, if you constantly train and strengthen your abdominals without training your lower back you will soon suffer lower back pain, poor posture and gradual curvature of the spine as your stronger “front” muscles pull against your weaker “back” muscles.

Unless you train to correct these imbalances, the dominant muscles will continue to gain strength as their opposing muscles continue to weaken.

Muscle Definitions

When discussing opposing muscles or muscle groups, the muscle that initiates movement is the agonist while the supporting or opposing muscle is the antagonist. A simple example, when you curl a dumbbell, your bicep is performing the work, both when you curl the weight up and when you lower the weight with a controlled movement. Your bicep is the agonist and your tricep is the antagonist. Agonist muscles are also referred to as prime movers as they literally make that particular movement happen.

But now flip the movement, hold the dumbbell behind your head and press upwards and perform a tricep extension. In this movement, your tricep is the agonist both as you push the weight upward and as you slowly lower the weight back behind your head. Your bicep is the antagonist. As you perform each exercise in your current training program, learn to recognize which muscle is “working,” which muscle is the agonist, which is the antagonist and what exercise could you add to train that antagonist.

There is a third type of muscle known as the synergist muscle. Synergist muscles are smaller muscles (usually near a joint) that support and assist an agonist muscle as it moves. Synergist muscles may also be fixators, literally fixing or stabilizing a joint so that movement can occur. An example would be the smaller muscles at your hand (holding the dumbbell), at your wrist, and at your shoulder as you perform dumbbell curls.

Opposing Muscle Groups

Not only are there opposing muscles, but also opposing muscle groups, and as a bodybuilder, powerlifter or weightlifter you should always focus on these groups over individual muscles. Full body or multi-joint exercises produce greater gains in size and strength over isolation exercises. Your major muscle groups are your chest, arms, shoulders, back and legs. You’ll notice these major muscle groups are made up of relatively larger muscles that move larger joints, to be more specific:

  • Your shoulder and upper back – Deltoids and Latissimus Dorsi
  • Your chest and upper back – Pectoralis Major and Trapezius
  • Your stomach and lower back (core) – Abdominals and Erector Spinae
  • Your hips (both flexion and extension) – Iliopsoas and Gluteus Maximus
  • Your hips (legs in/out to the side) – Hip Adductors and Gluteus Medius
  • Your thigh (extension and flexion from the knee) – Quadriceps and Hamstrings
  • Your lower leg – Tibialis Anterior and Gastrocnemius (calf)
  • Your upper arm (from the elbow) – Biceps and the Triceps

Smaller opposing muscle groups include your wrists, ankles and neck. Your neck extensors and flexors move it forward and back and side to side. Your wrists and ankles are also moved by extensors and flexors.

How To Train Opposing Muscle Groups

One of the oldest (and most effective) approaches to training opposing muscle groups is the Push/Pull Split program. Pushing exercise targets include chest, shoulders and tricep movements while pulling exercises include many back training exercises such as deadlifts, bent rows and pulldowns (or pull-ups).

Imagine yourself on your back on the bench press with a moderately heavy dumbbell in the racks. You grab the bar and perform 10 bench presses, rack the weight and while still grasping the bar, you pull your chest up to the bar, squeeze, hold and lower your body back to the bench and repeat ten times. You have just completed a very simple push/pull exercise that trains both chest and back. A more common push/pull combination would be bench press versus seated row or bent barbell row.

Push/pull split programs are for more experienced trainees due to the intensity and volume of work. There are a variety of ways to set up your split, one of the more popular is 2 on, 1 off, 2 on. Most programs combine push exercises on Day 1, pull exercises on Day 2 and then a rest day and then repeat. This approach will ensure that you train both agonists and antagonists in equal fashion to avoid imbalances.