Even if you lift heavy or light weights for 12 weeks, your body’s short-term hormone spike after each workout doesn’t change—and that means those hormone surges probably aren’t why your muscles get bigger or stronger over time.

If you're a guy who lifts weights, doing more reps with lighter weights (which spikes your hormones more) doesn't build more muscle or strength over 8 weeks than lifting heavier weights with fewer reps—even though the hormone changes look different.

Even if your hormones spike a lot right after your first few workouts, that doesn’t mean you’ll grow more muscle or get stronger later on.

Even after a super hard workout, the body’s baseline testosterone level doesn’t stay high the next day — it goes back to normal quickly.

When young men lift weights regularly for 15 weeks, their body’s immediate hormone spike after each workout stays about the same—no matter how many times they do it. It’s like their body keeps reacting the same way every time, without getting used to it.

Doing weight training either heavy or light until you can't do another rep for nine weeks doesn't change your hormone levels in your saliva, and that's okay—your muscles can still get stronger and bigger even if your hormones don't budge.