Train Movements or Muscles?
The Functional Strength Training Debate Continues
To correct muscle imbalances, the body should train movements AND muscles.
An example of a muscle imbalance is when a stiff lower back causes the hamstring muscles to be tight and the adductor (groin) muscles become weak. Fitness professionals have two theories to correct this problem. One is to train movements like a side lunge with a twist. The other is to place the affected person onto an adductor machine, isolating and training the muscles.
While training movements, many muscle groups work together to perform the function. During a side lunge with a twist, the adductors contract to move the leg to the side, the hamstrings passively stretch, the adductors (hips) inhibit unwanted motion, the core muscles twist the body and the shoulders stabilize the load. The movement theory is that the weak adductor muscle will adapt to the movement and become strong. The tight hamstring muscles will be forced to stretch. Eventually, the body, which seeks balance, will find it.
The movement proponents will say training muscles is useless and potentially dangerous. In everyday life, the body never uses only one muscle group. Functional, multi-joint exercises mimic body movement and will enhance athletic ability. Doing so will also burn calories at a high rate.
While training muscles, even an isolated exercise like a biceps curl is technically a movement. With the exception of the face, it is impossible for the body to use only one muscle to perform any exercise. During a standing dumbbell biceps curl, the forearm and hand muscles hold the load, the triceps muscles passively stretch, the shoulders inhibit unwanted motion and the core stabilizes the entire body.
Advocates of isolating and training muscles say functional training will only enhance a muscle imbalance. In this case, the adaptation to functional movements will be that the tight, strong hamstring muscles will take over for the weak adductor muscles. The hamstrings will become even stronger and the adductors will continue to become weaker.
Which argument holds water? Both sides can show case studies where their theory worked better than the other.
The goal of exercise programs is to provide the body with an adaptation. An adaptation is an enhancement of bodily movements, resulting in aesthetic or athletic improvements.
The movement theory mimics daily and sporting actions and helps the body improve these activities, which is an adaptation. Training muscles increase their strength. This is an adaptation.
The theory that works best is a combination of training muscles AND movements. Training a movement will make the body move more efficiently. At the same time, if a muscle is weak, the fastest way to make it stronger is to isolate it. Train the movement first because a movement requires more energy. Train the muscle second. The combination of movements and muscles is hard to beat.
The "Functional Strength Training" article discusses this issue further.
Sources
The Essence of Functional Training: Breaking the Bonds of Traditionalism Training Guide by Juan Carlos Santana
CPT: Optimal Performance Training For the Fitness Professional - National Academy of Sports Medicine
The Anatomy of the Human Body, 20th Edition by Henry Gray
Muscle Mechanics by Everett Aaberg
