How Motor Units Really Fatigue and Recover: Implications for Resistance Training

This presentation will provide an explanation of how muscle motor units are recruited through the full range of voluntary efforts, and how they subsequently fatigue (when active) and recover (when turned off). A model will be presented that explains individual motor unit fatigue progression and recovery during exercise and work, and this is crucial to understanding what happens to the whole muscle. An emphasis will be placed on demonstrating that low-load, high repetition resistance training challenges the highest threshold (ie. fastest twitch) motor units, as has been demonstrated with recent findings of similar strength and hypertrophy gains with both acute high- and low-load resistance exercise.