Most studies on intense weight training don’t check how well people recover afterward, so we can’t tell if the training helped, hurt, or caused serious burnout.

Right now, scientists don’t agree on how to diagnose or study overtraining in weightlifting, so it’s hard to tell the difference between being productively tired, overly tired, or actually burned out.

When people do really intense weight training, not everyone gets overly tired or performs worse — in fact, more than half of the studies didn’t see a drop in performance.

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.

Doing the same intense weight workouts all the time might lead to worse performance and overtraining in people who already lift regularly.