When you first start lifting weights, your muscles might look bigger right away—but that’s mostly because they’re swollen from tiny tears and fluid buildup, not because they’re actually growing stronger or larger for good.

After about 10 weight workouts, your muscles don’t just look puffy from water anymore—they actually start getting bigger because the muscle fibers themselves are growing.

If you're someone who's been lifting weights for a while, doing the same amount of heavy training over 9 weeks will make your thigh muscles grow by about half a centimeter — whether you spread your workouts over 2 or 4 days a week.

Doing more sets, reps, and lifting heavier weights doesn’t always mean you’ll grow bigger muscles—some people see big gains with less volume, while others don’t grow much even with more work.

If young guys lift weights for eight weeks—whether they go heavy or do more reps—they’ll likely build muscle in their upper body and back, and that can be seen with ultrasound scans.

Acute muscle swelling responses following a single resistance training session are not representative of swelling responses observed after prolonged, repeated training programs.