After four weeks of strong, held ankle lifts, your nerve signals to the muscle get faster during moderate efforts, making your muscle stronger without needing more muscle mass.

Your muscles don’t fire faster when you start or stop pushing—only when you’re holding a steady push—after four weeks of strength training.

Even though your nerves fire faster after training, they still respond to how hard you’re trying at the same rate—your brain’s control system didn’t get more sensitive.

After training, your tendons get a bit looser, so your muscles can start working sooner when you try to push, making you feel stronger faster.

If young, healthy guys lift weights for 12 weeks, their muscles get stronger at moderate speeds — like kicking or swinging — and they can generate 13% to 32% more force, no matter how they did the lifting.

When young men do isometric leg exercises for 12 weeks, their thigh muscles get bigger—and that bigger muscle size helps explain about 1 in 5 of their strength gains, even if their nerves aren’t getting better at telling muscles to work harder.