Motor Unit

Advanced ⚽ Sports / Fitness

Definition

A single nerve fiber and all the muscle fibers it controls. Recruiting more motor units = more force production. It's why you scream when lifting heavy—recruitment increases.

Example Usage

Heavy loads recruit high-threshold motor units, producing greater strength adaptations.

Origin

Neurophysiological concept; applied to exercise science and strength training.

Fun Fact

Motor unit recruitment follows Henneman's Size Principle: low-threshold units recruit first, high-threshold units only at high intensity—this is why heavy weight > light weight.

Source: Exercise Physiology, neuromuscular science