Essentials of Strength Training and Conditioning Practice Test 2026 - Free Practice Questions and Study Guide

When training stops, the first loss of strength comes from the nervous system, not from shrinking muscles. The nervous system reduces its ability to activate muscle fibers efficiently: fewer motor units are recruited, the rate at which those units fire (rate coding) drops, and the timing and coordination between muscles can become less precise. This neural drive to the muscle weakens quickly, so maximal force and rapid force development decline even before noticeable muscle atrophy occurs.

Over a longer period of disuse, muscle size and contractile properties also decline, which adds to strength loss, but the early drop is mainly about the nervous system’s reduced activation. Circulatory, digestive, or respiratory changes aren’t the primary drivers of that early decrease in strength.