According to veteran strength coach Charles Poliquin, repetitions are one of the most important training variables. Repetitions should dictate the load. The goal of any set is to do the most amount of weight that you can do with proper technique for the given number of repetitions. Therefore, by selecting a specific repetition range you are also selecting an appropriate load and what you select in for these will determine the training response.
When it comes to sets and reps, mainstream fitness often gives the following guidelines:
“If you want to get big use heavy weight and low reps.”
“If you want to tone and define, use high reps and light weight.”
While there can be some truth to these statements, it is just not that simple.
Goals and Repetition Ranges
Note: the set and rep examples written below are listed as set x reps (i.e. 3x5 = 3 sets of 5 reps)
The 1-5 Repetition Range:
1-5 reps builds strength. If you want to build relative strength (i.e. improve strength-to-weight ratio) the volume should be low (e.g. 2x5, 4x4, 3x3 or 5x2) and calorie level should be kept at maintenance. This repetition range can be used as part of functional hypertrophy (i.e. get bigger and way stronger) program if the volume is increased (e.g. 5x5, 6x4, 8x3) and the nutrition is tailored toward building muscle mass.
The 6-8 Repetition Range:
6-8 reps are typically used for strength-hypertrophy. This is a great repetition range for someone who wants to get bigger and stronger. However, if the desire is to get bigger again there will typically be a need for higher volume (e.g. 4x6) and some mass building nutrition. Though not as good as the 1 to 5 repetition range, this rep range can be used to build some strength without size by decreasing the volume (e.g. 2-3x6) and not following the mass building eating plan.
The 9-12 Repetition Range:
9-12 reps can be used for many different purposes. If this rep range is put into a bodybuilding program and combined with a bodybuilding diet, a trainee will gain nonfunctional muscle mass (i.e. the trainee gets bigger without getting correspondingly stronger and thus decreases his or her strength to weight ratio). (Note: athletes needing to gain muscle size and weight can use this rep range for part of their training program and provided there is some heavy strength training as well, they should be fine). If used in a whole body general fitness routine, this repetition range will build strength-endurance (a happy mix of strength and endurance - though neither one will be elite). This is also a great repetition range for smaller accessory exercises (e.g. lower traps, rotator cuff, grip, forearms, abs, neck and direct arm work).
The 13+ Repetition Range:
13+ reps are useful for muscular endurance. In some cases, this can help build nonfunctional hypertrophy. For example, in some muscle groups such as the quadriceps, high repetition exercises (e.g. squats done for 20-50 reps) can build nonfunctional hypertrophy as well as . This can also be used to build lactic acid tolerance and may be appropriate for some accessory exercises. Contrary to popular belief, this repetition range is not in and of itself effective for tone and definition. Tone refers to the level of hardness in the muscle. In well toned muscles, the muscle will appear hard and almost flexed even at rest. This is due to an increased level of electrical activity in the muscle. The truth is that heavy weight low rep training is what builds this tone. A lean (i.e. has a low % of body fat) strength and power athlete will always have harder muscles than an endurance athlete. Definition refers to the ability to see the muscle because of low levels of subcutaneous body fat. While intense exercise obviously plays a role in this, nutrition is the most important changeable factor (genetics also plays a role this) as to whether one will have good muscle definition or not. Doing high reps and low weight training is significantly better than watching TV, it is inefficient way to train for definition.