If guys who lift weights train too much — like a whole lot in a week — their bodies might get stressed in a way that could hurt their performance, and scientists can see this stress through certain markers in their body.

In guys who lift weights a lot, certain chemicals in their urine that show stress on the body are closely linked to both worse performance and more training — meaning they might help tell when someone’s overdoing it.

When guys who work out regularly do a 12-week weight training program, their body's uric acid goes up more and more as the program goes on, especially by the end — which might mean their bodies are under increasing stress from the workouts.

Doing more sets of weightlifting each week helps you build more muscle, but after a certain point, adding even more sets gives you less extra benefit.

Lifting more weights each week makes you stronger, but the extra strength you gain from each additional set gets smaller faster than the muscle gains do.

Lifting weights more often helps you get stronger, but after a certain point, you don’t get much stronger no matter how much more you lift—plus, this slowdown happens sooner for strength than for muscle growth.