Which of the following is a symptom of overtraining?

Fatigue is a well-documented symptom of overtraining. Overtraining occurs when an individual trains beyond their body's ability to recover, leading to a decline in performance and various physical and psychological symptoms. One of the most common signs is chronic fatigue, which can manifest as a persistent sense of exhaustion after workouts, decreased energy levels, and a reduced motivation to exercise.

The body's systems, including hormonal balance, immune function, and nervous system response, become disrupted due to the excessive strain placed upon them without adequate recovery time. This can result in not just feelings of tiredness, but also physical and mental fatigue that impacts overall well-being and performance.

In contrast, increased muscle mass, improved endurance, and heightened energy levels are typically associated with well-structured and balanced training programs that allow for recovery and adaptation. These outcomes indicate successful training, whereas fatigue signals that the body may be overwhelmed and is in need of rest and recovery to prevent further complications.