If healthy adult men do resistance training for more than two weeks, they will reliably gain about 1.5 kilograms of muscle. This shows that lifting weights is a very effective way to build muscle overall, no matter how you measure it.

If healthy guys between 18 and 40 lift weights regularly for at least two weeks up to a year, they typically gain about 1.5 kilograms of muscle—no matter what kind of weight routine they follow.

If a young, healthy man lifts weights for 8 weeks, his muscles will likely get bigger—by about 6%, give or take a little.

Lifting weights helps adults gain muscle — studies show it consistently leads to modest muscle growth when done regularly.

If you lift weights, your muscles grow by roughly the same amount no matter which body scan or measurement method you use to track it. This means you don't need to worry about which specific machine or technique you use to see your progress, as they all show similar results.

If you are new to weightlifting or already have years of experience, you will likely build muscle at roughly the same rate when following the exact same workout program.