Check the inputs first
Before blaming training, look at sleep under 7 hours, a steep calorie deficit, and life stress. These drain recovery far faster than your workouts do. Fix those and the fatigue usually lifts within a week.
True overtraining is rare; most gym fatigue is under-recovery from poor sleep, low calories or a spike in volume.
Genuine overtraining takes weeks of hard overreaching and is uncommon for most lifters. What you likely have is under-recovery: bad sleep, an aggressive deficit, or a sudden jump in sets. Warning signs are lifts dropping across several sessions, sleep getting worse not better, and resting heart rate climbing.
Before blaming training, look at sleep under 7 hours, a steep calorie deficit, and life stress. These drain recovery far faster than your workouts do. Fix those and the fatigue usually lifts within a week.
Strength falling for 2 or more sessions in a row, elevated resting heart rate, disrupted sleep and lost appetite point to overreaching. One tired day after a hard leg session is just normal fatigue.
Take a week at roughly half your usual sets and lighter loads. If you bounce back strong, you were overreached. If nothing changes, look at sleep, nutrition or an underlying illness.
If deep fatigue, a racing resting heart rate, or feeling unwell persists past a deload week, see a doctor to rule out illness or other causes.
True overtraining is rare; most gym fatigue is under-recovery from poor sleep, low calories or a spike in volume.