In advanced male judo athletes, six weeks of resistance training that induces muscle hypertrophy is associated with a reduction in power output relative to muscle cross-sectional area (Pmax/CSAindex), especially among those undergoing heavy-load training to failure, indicating that increased muscle size may not enhance—and might impair—mechanical efficiency of force production in already highly muscular individuals.

When advanced judo athletes train with heavy weights until muscle failure, their muscles grow bigger, but the way their nerves activate those muscles changes — instead of firing more efficiently, the nerves recruit more muscle fibers at once in a less coordinated way, which makes each unit of muscle produce less power. This is seen in studies where bigger muscles didn’t lead to more power output relative to size, especially after training to failure (10.1371/journal.pone.0307841).