If new guys do leg exercises with slow reps (6 seconds) instead of faster ones (2 seconds), they might get stronger in a specific knee position—even if they do the same number of sets and their muscles grow the same amount.

If untrained guys do leg exercises to failure using medium-heavy weights, going slow or going a bit faster on each rep gives about the same strength gains.

When young guys who don't work out do leg exercises until they can't do any more for 10 weeks, lifting lighter weights and heavier weights both build muscle about the same amount.

If young guys stick to the same exercises every time they work out for about two months, they get stronger in a specific leg test than if they keep switching up their routine.

If new guys do leg exercises to failure using medium weights, slowing down the movement doesn’t make their muscles grow more than doing faster reps — both ways work about the same.

If you're new to lifting and using light weights, you need to push your muscles until they can't do another rep to grow them bigger—otherwise, even doing more reps won't help.