What occurs during overtraining?

Overtraining occurs when the body's recovery ability is exceeded due to excessive training volume or intensity without adequate rest. This condition leads to decreased performance, fatigue, and potential injury, as the body doesn't have enough time or resources to repair and strengthen itself after workouts. Athletes experiencing overtraining often show signs of increased resting heart rate, mood swings, sleep disturbances, and overall reduced physical readiness.

In contrast, the other options do not align with the concept of overtraining. Training volume being too low or training being perfectly balanced would typically not lead to overtraining; instead, these scenarios could promote recovery and performance improvements. Prioritizing recovery over training is a strategy to prevent overtraining, rather than a characteristic of it. Hence, the identification of recovery ability being exceeded as the defining issue in overtraining makes it a clear and correct choice.