When people who already lift weights do either short breaks between reps (cluster sets) or long continuous sets (traditional sets), both ways make their muscles grow about the same amount if they work just as hard and do the same total number of reps.

If you’re already experienced with weightlifting, doing either kind of set—short breaks or long continuous sets—will make your muscles grow, as long as you’re working hard and doing the same total amount of work.

If you’re already experienced with weightlifting and train your legs twice a week for 8 weeks with hard sets, your muscles will grow whether you take short breaks between reps or not.

If you're a young guy lifting weights, your muscle growth and strength gains might be easier to predict if you treat big multi-muscle exercises (like squats) differently in your workout plan than isolated moves (like bicep curls).

This study only looked at the front and side of the thigh—so we don’t know if doing more sets helps your front thigh or hamstrings grow more.

If you're already experienced with weight training, doing the exact number of sets your past logs suggest (1.2 times your usual) builds more muscle than doing a fixed number of 22 sets every week — and this is shown by measuring your thigh muscle thickness with ultrasound.