When healthy young men do slow, low-effort weightlifting exercises, their muscles work longer and use more oxygen than during faster or higher-effort exercises in a single workout session.

Doing slow, controlled weight lifts with light weights can make your muscles use up more oxygen during the workout than doing the same lifts fast or lifting heavy weights—even if the heavy lifting feels harder.

Doing slow, gentle weight training can build muscle and make you just as strong as lifting heavy weights quickly.

Slow, low-effort weight training keeps your muscles working hard and starves them of oxygen more than fast, heavy lifting, which might help build muscle and strength just as well by stressing the muscles in a different way.

When trained guys do lots of reps, they feel more tired, weaker longer, and more stressed than when they do fewer heavy reps — even though their muscles are damaged about the same.

Doing slow, low-intensity weight training twice a week for about three months can build muscle and strength almost as well as fast, heavy lifting in young men who don't normally exercise.