If you mix up your workouts for the same muscle, you’ll grow that muscle more evenly than if you always do the same exercise.

If young guys who haven’t worked out in a while switch up their strength exercises for the same muscles, they’ll likely build muscle more evenly across their thighs and arms over nine weeks compared to doing the same moves every time.

If you mix up your strength workouts for the same muscle, it might help it grow more evenly from top to bottom, especially if you haven’t been training for a while.

Some people think mixing up your leg workouts (like changing weights or angles) might make all parts of your quadriceps grow better than doing the same routine over and over—but right now, science hasn’t proven this for sure.

If you lift weights until you're almost too tired to do another rep, you'll likely build bigger muscles—but your strength gains won't be any better than if you stopped earlier, as long as you're doing the same total amount of work and lifting the same weight.

People grow muscle at very different rates — but each person tends to grow their arms and legs similarly, no matter what weight they use. This means your genes and biology matter more than how heavy your weights are.