The document discusses overtraining and how to avoid it. It defines overtraining as a physiological state characterized by an excess of stress on the nervous, immune, and hormonal systems that leads to sustained decreases in physical and mental performance. Signs of overtraining include lack of energy, soreness, sleep problems, and decreased strength. Causes include training too intensely, doing too much volume, or continuing a workout when motivation drops. To avoid overtraining, one should use proper nutrition, get enough sleep, and consume omega-3 fatty acids to support recovery of the body and brain.