Lifting light weights at a normal pace three times a week for 12 weeks doesn't make muscles bigger or stronger in young men, even if you do the same total amount of work as other exercises.

Doing slow, low-effort weight training three times a week for 12 weeks can make your thigh muscles bigger and stronger, just as much as doing fast, high-effort weight training.

In physically active young men, six weeks of resistance training three times per week at 60% of one-repetition maximum produces the same increases in muscle size and strength whether using full range of motion or partial range of motion.

If older men in their early 70s lift heavy weights three times a week for four months, they’ll get noticeably stronger and their big muscle fibers will grow bigger.

For older adults between 59 and 76 years old, doing gentle strength training twice a week for 12 weeks makes them stronger but doesn't build much muscle size.

If young guys lift weights all over their body 3 times a week for 9 weeks, they'll get stronger — no matter if they switch up their exercises or stick to the same ones.