Final answer:
The statement is true as sympathetic overtraining and parasympathetic overtraining are the two primary physiological markers of overtraining, reflecting imbalances in the body's stress response and recovery processes.
Step-by-step explanation:
The statement that the two most common physiological markers of overtraining are sympathetic overtraining and parasympathetic overtraining is True. In the context of the autonomic nervous system, the sympathetic nervous system is activated by stressful situations, thus it is responsible for the 'fight-or-flight' response. Conversely, the parasympathetic nervous system functions to conserve energy and is involved in 'rest and digest' activities, reducing the heart rate, and aiding in digestion and recovery.
With repeated stress or overtraining, the balance between these two systems can be disturbed, leading to either sympathetic or parasympathetic overtraining. Sympathetic overtraining is characterized by heightened alertness and a decreased ability to rest, whereas parasympathetic overtraining can manifest as excessive fatigue, decreased motivation, and mood disturbances.