Written by Brad Schoenfeld, Ph.D., CSCS, FNSCA
29 July 2019


High or Low Reps for Muscle Gains?

Science Determines the Ideal Rep Range


One of the age-old fitness questions is whether a powerlifting-type routine can build as much muscle as a bodybuilding-type routine. On the surface, it would seem that the bodybuilding routine has a clear advantage in this regard. After all, it’s no secret that bodybuilders are generally bigger than powerlifters. If low reps and long rest intervals were the key to getting huge, then every bodybuilder would be training like a powerlifter, right?

     While this premise might seem logical, science tells us that logic doesn’t always translate into practice. In order to accurately assess which type of training packs on the most mass, it’s necessary to carry out controlled research where variables are strictly controlled. Only then can you draw a true cause-effect relationship on results.

     A recent study from my lab11 sought to provide clarity on the topic in well-trained men (4+ years average lifting experience). Subjects were randomly assigned to perform either 1) a powerlifting-type routine using low reps (2-4 per set) and long rest intervals (three minutes between sets), or 2) a typical bodybuilding-style workout with moderate reps (8-12 per set) and shorter rest intervals (90 seconds between sets). Total volume-load (reps x sets x load) was equated between groups to ensure that any differences would not be confounded by the amount of work performed. Thus, the powerlifting group performed seven sets per exercise while the bodybuilding group performed three sets. All sets were performed to the point of momentary concentric muscular failure. Training was carried three times a week for eight weeks.

     The results might surprise you. While both groups significantly increased muscle mass, there were no differences noted between groups. In other words, both groups gained approximately the same amount of muscle over the course of the study, regardless of rep range! Interestingly, while both groups significantly increased their one-repetition maximum (1RM) in the squat and bench press, there was a slight edge to the powerlifting group in terms of strength gains.

     Here’s the rub: Total training time in the powerlifting group was about 70 minutes, while that of the bodybuilding group was just 17 minutes. So from a time-efficiency standpoint, bodybuilding-type training produced similar hypertrophy (as well as nearly similar strength increases) in about a quarter of the time as the powerlifting routine.

     What’s more, exit interviews with participants in the powerlifting group indicated that they were fried by the end of the eight-week study. Virtually all said they had sore joints and complained of being mentally fatigued from the constant grind of performing heavy, low-rep sets; two of the subjects in the group dropped out from overuse injuries. Had the study gone on any longer, I’m certain these lifters would have become overtrained and ultimately seen a regression in results. On the other hand, those in the bodybuilding group reported feeling fresh. They were eager to get back in the gym, with many expressing a desire to increase training volume and frequency.

     So here’s the take-away message: While it appears that muscle growth can be similar with both heavy and moderately-heavy loads, provided that volume is equated, it just isn’t practical to constantly train with high volumes and heavy loads over time. Understand that there is a clear dose-response relationship between volume and hypertrophy whereby higher training volumes correlate with greater muscle growth, at least up to a certain point.7,10,13 Because of the long rest periods and additional sets needed to equate volume in the powerlifting group, our study was only able to include three total exercises per session for a limited number of muscle groups (back, chest and thighs). That’s simply not sufficient to maximize whole-body hypertrophy.

     All things considered, the best approach to maximizing muscle mass is to train with a combination of low and moderate reps. The typical “bodybuilding rep range” should form the basis of a hypertrophy-oriented routine as it allows the performance of a greater amount of volume without overtaxing the neuromuscular system. That said, don’t hold exclusively to such training. Adding in some heavy-load sets in the 1-5 RM range helps to maximize strength, which ultimately allows the use of heavier loads during moderate-rep lifting. And lifting heavier without compromising the number of reps increases mechanical tension in muscles— a primary driving force for muscle growth. The old-school bodybuilders like Arnold and Franco used this approach with great success. Seems like they had it right all along.

     Brad Schoenfeld, Ph.D., CSCS, FNSCA is widely regarded as one of the leading authorities on training for muscle development and fat loss. He has published over 60 peer-reviewed studies on various exercise- and nutrition-related topics. He is also the author of the best-selling book, The M.A.X. Muscle Plan, and runs a popular website and blog at www.lookgreatnaked.com.