Repetitions refer to the number of times you complete one routine exercise at a given set. For instance, your trainer gave you three sets of pull-ups, each with 20 repetitions. So, you’ll need to perform a total of 60 pull-ups with a short rest between 20 times.  Here are the recommended maximum repetitions for every type of goal: 1 to 5 reps: a low-rep routine with heavy loads can develop muscle strength. 6-12 reps: a medium rep routine is recommended for muscle growth. 12-20 reps: a high-rep routine for building muscular endurance Remember that the recommendations above are only for 1 set, which means you must start over again after your rest period until you complete the required number of sets. Other research suggest that some bodybuilders respond to higher repetition ranges during muscle building.