How Many Reps Should I Do?

Various repetition ranges can be used to achieve different fitness goals, to add variation to workout programs, and to maximize the benefits of a specific exercise. Additionally, other less generalizable factors may contribute to the determination of the “best” number of reps to be completed by an individual, such as personal preference, history of injury, and current energy level.

The standard guidelines for selecting a rep range, often referred to as the “strength-endurance continuum,” distinguish the ranges by fitness goals: strength, hypertrophy, and endurance.

In general, strength goals are best approached with low repetitions (1-5) of heavy loads, whereas muscle growth is optimized at a moderate rep range (6-10 or 8-12), and endurance is trained with higher rep ranges (11-15 or more; Campos et al., 2002; Schoenfeld et al., 2021). Some studies suggest that number of reps–within a reasonable range of about 3 to 20 reps–does not meaningfully impact gains in strength, hypertrophy, or endurance (Carpinelli et al., 2004).

Completion of an exercise near failure may be a factor more relevant to enhancing the effects of resistance training. However, rep ranges must be considered in resistance training programs and can be used to increase the specificity of training in relation to fitness goals and to enhance the efficiency and enjoyability of a workout.

Low reps (about 1 to 5 reps per set) allow for training at heavy loads in contrast to moderate or high rep ranges. So, low reps are great for improving maximal strength and power. Low reps can also be more enjoyable and less mentally intimidating. When using heavy weights, low reps prevent form breakdown and consequent injury. On the other hand, low reps may not allow a beginner to get sufficient exposure to a new exercise. Heavy loads can also be hard on joints and increase the risk of injury. Moreover, if muscular endurance is a goal, low reps are not the most useful approach. Exercises that work well at low reps include highly powerful and/or explosive movements, such as plyometrics and powercleans, exercises that are suitable for one rep max testing (or those that can be loaded heavily), like barbell deadlift, barbell squat, and benchpress, or exercises that are especially fatiguing and challenging, such as unassisted pull-ups.

You would want to avoid doing a low number of repetitions of single-joint or isolation exercises since a heavy load that is not distributed among several muscles, joints, etc. may increase the risk of injury. Low reps would also not be suitable for light resistance training, like lateral raises, or non-explosive, relatively easy bodyweight exercises, like crunches. 

Using a moderate rep range (6-12) is thought to be best for promoting muscle growth. Another advantage is that 8 or 10 reps occupies a nice middle ground between intense low reps and exhausting high reps, both of which can be intimidating and, for some, dangerous. This rep range may also be good for beginners who need to practice a motion repeatedly without approaching fatigue that would hinder safe form. Moderate rep ranges are also time efficient since they allow for an individual to complete many reps in fewer sets than if using low reps and with less rest than if using high reps. Moderate rep ranges, as implied by the fairly linear load-to-repetition relationship, are not great for super heavy or super light resistance training. Using 6-10 instead of 1-5 or 15+ reps may also lack specificity to an individual’s training goals, especially if those goals include building maximal strength and power or endurance. 

High rep ranges are the best way to increase endurance. If an individual needs to be able to lift 100 light boxes for his job every day, then he needs to be able to ward off muscular fatigue. High rep ranges are also good for beginners who need a lot of low-weight practice to improve form. Also, high reps can be used for conditioning to get the heart rate up, burn more calories, etc. On the other hand, high reps can be mentally (not just physically) tiring and unsustainable (e.g., most people couldn’t make themselves do 50 reps of multiple or maybe even 1 exercise every time they go to the gym). Repeated motions also increase the risk of irritation and discomfort, including prolonged issues like tendonitis.

High reps are also not able to increase strength to the extent that heavy loads in low reps can, and injury may be more likely if form is not maintained throughout all the reps. High reps are good for many low weight exercises, such as those completed with cable machines or dumbbells, or body weight exercises, like jumping jacks. High reps are also suitable for single joint exercises that may be safest and most effective at low resistances, like hamstring curls. High reps should not (and cannot) be used for exercises completed at loads close to a 1 rep max or for exercises that are super explosive and/or technical, like power cleans and snatches. 

-Hanna Reuter

References

Campos, G. E., Luecke, T. J., Wendeln, H. K., Toma, K., Hagerman, F. C., Murray, T. F., Ragg, K. E., Ratamess, N. A., Kraemer, W. J., & Staron, R. S. (2002). Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones. European Journal of Applied Physiology, 88(1-2), 50–60. https://doi.org/10.1007/s00421-002-0681-6

Carpinelli, R., Otto, R., & Wientt, R. (2004). A critical analysis of the ACSM position stand on resistance training: Insufficient evidence to support recommended training protocols. Journal of Exercise Physiology Online, 7. 

Schoenfeld, B. J., Grgic, J., Van Every, D. W., & Plotkin, D. L. (2021). Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum. Sports (Basel, Switzerland), 9(2), 32. https://doi.org/10.3390/sports9020032