For men who already lift weights, doing either high-intensity or high-volume workouts for 8 weeks didn't make a big difference in leg strength or muscle size.

Even if you’re already strong—squatting almost twice your body weight—adding more sets will make you stronger, but won’t make your muscles grow more than doing a moderate amount.

If you're a guy who's already used to lifting weights, doing heavy sets with long rests works just as well as doing more reps with shorter breaks when it comes to getting stronger in the squat after 8 weeks.

Untrained young men who perform resistance training twice a week for eight weeks at moderate intensity show measurable increases in maximal strength for the bench press, bent-over row, and back squat, with strength gains ranging from 20% to 40%, regardless of how the sets are organized.

If you're a guy who's been lifting weights for a while, doing either 2 or 4 workouts per week for each muscle can boost your strength by about 8–11% in just 8 weeks—as long as you do the same total amount of work overall.

If you're already strong and lift weights, training each muscle group either once or five times a week for eight weeks will give you about the same strength gains on the bench press, squat, and row.