Brazilian gym teachers who train a lot each week don’t seem to get overtrained — but the study didn’t actually measure key body signals like stress hormones or muscle damage, so we can’t be sure.

Brazilian gym teachers and fitness pros who train hard—over 5 hours a week—say they don’t feel overly tired or burned out, and their survey scores show they’re doing okay mentally and physically.

There's no single blood test or clear sign that can definitively tell if someone has overtraining syndrome. Doctors instead use a mix of mood surveys and lab tests like cortisol or testosterone, but none of these are very accurate on their own.

There's no single blood test or clear sign that doctors can use to diagnose overtraining. Instead, they rely on a mix of how you feel (like mood and fatigue) and lab tests (like hormones and inflammation), but none of these are very accurate on their own.

Brazilian gym teachers and fitness pros say they don’t feel bored or overly tired from their workouts — even though they train a lot — which suggests their routines stay fun and fresh.

To diagnose overtraining in athletes, doctors need to rule out other health issues like low nutrients, infections, or energy deficiency, because those can cause similar symptoms and often happen at the same time as overtraining.