When you start lifting heavy weights, your brain and nerves get better at telling your muscles to work harder faster — and that’s why you get stronger so quickly at first.

Lifting heavy weights makes your muscles stronger, and that happens because your brain gets better at telling your muscles how to work together, and your muscle fibers themselves grow bigger with help from special repair cells.

When you first start lifting weights, you get stronger not because your muscles grow bigger right away, but because your brain gets better at telling your muscles when and how to contract.

When you first start lifting weights, your muscles get stronger not just because they’re growing, but because your brain and nerves get better at telling your muscles when and how hard to contract.

When people do heavy weight training and their muscles get stronger, it’s not just because their muscles get bigger — their nerves also get better at telling muscles to work hard, and their muscle fibers change shape in ways that help them produce more force.

When your thigh muscles fire more strongly during a max effort leg push, you tend to get stronger faster after doing 12 weeks of holding a knee extension position — and this muscle firing explains about 30% of why some people get stronger than others.