Athletes who are really overtrained might feel more depressed or moody than those who are just temporarily worn out, and these mood changes could be an early red flag that something's wrong.

Athletes who are overtrained tend to feel more tired, stressed, sad, or confused—and less energetic—than healthy athletes. Tracking these feelings might help spot overtraining.

Overtraining isn't just being tired — it's when an athlete's body stops working properly and performance drops for a long time, even after resting, and it's different from regular burnout that goes away in a few weeks.

If someone's strength keeps dropping during weight training, that might be the best sign they're overtraining—because no blood test or body measurement has proven to reliably catch it early.

Paralympic athletes who train too much without enough rest or fuel might be more likely to get stress injuries in their bones, especially if they do endurance sports like racing or long-distance events.