When trained lifters slow down their bench press reps by half, it helps them build bigger chest muscles and do more reps.

For men who already lift weights, doing bench presses with heavy weights (70-85% of their max) for 8 weeks gives the best boost to chest muscle size, strength, lifting speed, and how many reps they can do.

When guys who lift weights slow down their bench press reps by about 25% from their fastest speed, it helps them get stronger faster than other training methods.

Lifting heavy weights with fewer reps and longer breaks makes your arms stronger and bigger faster than doing more reps with lighter weights and shorter breaks, especially for guys who already work out.

If you do the same total amount of weightlifting work, lifting heavy weights a few times or lighter weights more times gives about the same muscle growth in the chest for beginners doing bench press, showing that the total work matters more than how many reps you do.

When two different ways of lifting weights are adjusted so that the total time your muscles are under strain is the same, both ways lead to about the same strength gains and muscle growth in people who haven’t trained before.