A collegiate cross-country runner increases her mileage two months before the start of preseason conditioning. Because this will be her last year of collegiate competition, her mileage increases are significantly greater than in years past. She begins to notice that her muscles are more sore than usual after workouts. Her times remain good, and after an examination by the head athletic trainer she learns that her body composition, blood pressure, and resting heart rate are essentially unchanged since testing two months earlier. Is this athlete overtrained? What is the difference between overreaching and overtraining? If this pattern of unsupervised mileage increases continues, what might begin to happen to this athlete physiologically? Will her performance improve?