If young, healthy guys lift weights for 12 weeks, their muscles get stronger at moderate speeds — like kicking or swinging — and they can generate 13% to 32% more force, no matter how they did the lifting.

If young, healthy guys do strength training for 12 weeks using different types of muscle contractions—whether slow or fast—they’ll get significantly stronger in their thigh muscles, no matter which style they pick.

Getting stronger at lifting weights doesn’t make you much stronger at pushing or holding something still — they’re like two different kinds of strength, not just one ability measured two ways.

You can get stronger by doing hard exercises just once a week—even if they’re tough—without your muscles staying damaged or sore.

Being strong at lifting weights doesn’t mean you’re strong at pushing or holding something still—even with the same muscles—because your body uses different systems for moving vs. holding.

Lifting light weights for nine weeks didn't make people stronger on a machine that tests muscle power at different speeds, and in fact, their performance slightly dropped — while heavy lifting kept their strength steady.