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 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 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.

If you're already used to lifting weights, doing more sets and reps over time will help you build bigger muscles and get stronger — but only if you keep training consistently.

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.

If you're already trained in lifting weights, whether you use free weights or machines, you'll get about the same strength gains after 8 weeks—as long as you're lifting the same amount, at the same intensity, and moving through the same range of motion.