Even if your hormones spike after a tough workout, that doesn’t mean you’ll grow bigger muscles or get stronger over 12 weeks of training — the spike and the results don’t seem to go together.

When young men do intense leg workouts, their body releases more lactate and cortisol—stress and energy chemicals—but that doesn’t mean they’ll grow bigger muscles or get stronger faster than if those chemicals stayed low.

Even if your body releases a lot of muscle-building hormones after a workout, that doesn’t mean you’ll grow bigger muscles any faster than someone whose body releases way less—because studies show both people end up with the same muscle gains.

Even if your testosterone, growth hormone, and IGF-1 levels spike after a workout, that doesn’t mean you’ll grow more muscle over time—those hormone spikes don’t seem to explain why some guys get bigger than others after 16 weeks of lifting weights.

Just because your testosterone, growth hormone, and IGF-1 levels spike after a workout doesn't mean those spikes are what make your muscles grow.

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.