If you’re getting stronger lifting the same weights, you’re probably gaining muscle—even if the scale doesn’t move.

You can't really grow bigger muscles until you've done about 18 weightlifting sessions—your body needs time to adapt before it starts building real muscle.

To keep getting bigger and stronger muscles, you gotta slowly make your workouts harder over time—either lift heavier weights, do more reps, or do more sets.

You can build muscle just fine whether you rest for 30 seconds or 4 minutes between sets — the exact rest time isn’t a make-or-break factor.

If you lift weights, your muscles grow bigger — but only up to about 45 sets a week per muscle group; after that, you don’t get much extra growth no matter how much more you train.

Lifting weights three times a week instead of two makes your muscles grow bigger, no matter what type of muscle fibers you have — but it doesn’t make you stronger in one-rep max lifts.