No topic in the field of exercise has been more hotly debated over the past few decades than the amount of volume needed to maximize muscular gains. On one side of the controversy you have high-intensity training (HIT) adherents, who generally preach that a single set of an exercise is all that’s required to get jacked; proponents claim exceeding this dose not only isn’t beneficial but actually can cause regression due to overtraining. Nautilus founder Arthur Jones is often credited as the champion of this movement, and bodybuilder Mike Mentzer helped to popularize the concept in the late 80’s and 90’s.

On the other end of the spectrum are high-volume advocates who maintain that multiple sets are essential to fully stimulate muscle development. The vast majority of competitive bodybuilders subscribe to the latter theory, as shown in a recent survey whereby 95% of respondents reported to train with multi-set protocols.

In an effort to devise evidence-based guidelines, our lab previously carried out a meta-analysis on the effects of volume on muscle growth that was published 2017. In case you’re not aware, a meta-analysis pools the results from all studies on a given topic and then compare the data as if it’s one large study instead of multiple smaller ones. This helps to derive greater statistical power and thus draw conclusive practical inferences from the current research. Results of our analysis showed a fairly clear dose-response relationship, with higher volumes resulting in greater muscular gains.

While the findings of the meta-analysis appear compelling, there were a couple of shortcomings. For one, the vast majority of studies involved untrained subjects; only a couple of studies employed individuals with resistance training experience. This is important because the early phase of training is associated with a different adaptive response compared to the latter stages; thus, you can’t necessarily generalize findings to well-trained lifters. Moreover, we were not able to determine effects beyond 10 sets per muscle per week; there simply wasn’t sufficient research looking at higher training volumes to draw relevant conclusions as to what might be an upper amount of volume for continued gains.

With this in mind, we set out to fill in the gaps in the literature by carrying out a study on the topic, which has just been published in Medicine and Science in Sports and Exercise. Here’s the lowdown:

What We Did

45 young, resistance-trained men were randomly assigned to train with either 1, 3, or 5 sets per exercise; 11 subjects ultimately dropped out for various reasons, leaving a total of 34 participants who completed the study. A total of 7 exercises designed to work all the major muscle groups were performed each session (chest press, shoulder press, lat pulldown, seated row, squat, leg press, and leg extension). Subjects performed 8-12 reps per set, with all sets carried out to muscle failure. Training was carried out on 3 non-consecutive days per week for 8 weeks. The routines were fully supervised by the research team to ensure full compliance. Measurements included: 1RM strength in the squat and bench press; upper body muscle endurance in the bench press at 50% 1RM; and hypertrophy of the biceps, triceps, mid-thigh, and lateral thigh using ultrasound.

What We Found

All groups made substantial gains in maximal strength in both the squat and bench press over the 8-week study period, but the extent of the gains were strikingly similar between groups with no statistical differences detected. Results slightly favored the higher volume conditions for upper body muscular endurance on an absolute basis, but the differences didn’t reach statistical significance and were likely of no practical relevance.

Alternatively, there was a clear dose-response relationship for muscle hypertrophy, with 5 sets showing the greatest gains, followed by 3 sets and then 1 set. These findings were generally consistent for all muscles studied, and were most pronounced in the lower body musculature. The graph above presents a visual representation of the findings.

What We Learned

I must say, I was rather surprised at the strength findings here. I had anticipated that higher volumes would translate into greater increases in maximal strength.

Not the case.



Strength gains in the 1 set group were just as good as for the higher volume groups (see Figure 1). What’s more, these results were accomplished in a fraction of the time as the 1 set group trained for approximately ~13 minutes per session while the 5 set group’s sessions lasted ~68 minutes! So a major takeaway would be that, if increasing strength is your primary focus, then you can adopt a minimalist training approach and accomplish your goal in less than 45 minutes a week. Now this finding comes with the caveat that training was carried out in a moderate rep range (8-12 RM). I would speculate that if we used a true powerlifting range (3-5 RM) then you’d probably have to add some additional sets as the low number of reps per set would limit the amount of “practice” and thus require a higher volume.





On the other hand, results for hypertrophy were consistent with our meta-analysis on the topic, demonstrating that higher volumes are needed to maximize muscle growth. These results were consistent across all muscles studied (biceps, triceps, and quads). Moreover, there was generally a dose-response relationship noted, whereby 3 sets produced greater increases in size compared to 1 set, and 5 sets was superior to 3 sets. As shown in the in the accompanying graph (Figure 2), the magnitude of differences was quite stark. For example, biceps growth was 1.6%, 4.7% and 6.9% for the 1, 3, and 5 set groups, respectively. Volume had an even greater effect on quadriceps growth, with increases of 5.0%, 7.9, and 13.7% for the lateral thigh in the 1, 3, and 5 set groups, respectively. Similar spreads were found for growth in the mid-thigh region.

When quantifying the volume into sets per muscle per week as is often done in bodybuilding circles, the highest volume condition performed 30 sets/muscle/week for the biceps and triceps, and 45 sets/muscle/week for the thighs. I’d note that the majority of sets were carried out with compound exercises. Thus, the triceps were targeted with pushing movements (chest press and shoulder press) and the biceps were targeted with pulling movements (lat pulldowns and rows). Although the triceps and biceps clearly receive a good deal of work in these movements, the extent to which they are targeted is not clear; whether the results would have changed had we included single-joint exercises such as triceps pushdowns and arm curls remains questionable. Similarly, the lower body involved the performance of the squat and leg press, which not only work the quads but also involve substantial activation of the hip extensors. Again, it’s not clear how much stimulation the quadriceps receive in these movements compared to the other working muscles. We did include leg extensions for the lower body, which would provide more direct targeting of the quads.

Now, a few caveats to the findings that must be considered when attempting to extrapolate findings into practice. For one, the subjects were young, resistance-trained men who seemingly would be able to recover well from the effects of large volumes of intense exercise. It is reasonable to speculate that middle-aged and older individuals probably wouldn’t be able to recover as well from higher volumes of training, and thus might not respond as favorably or perhaps even have an impaired response.

Moreover, the study duration was relatively short, comprising 8 weeks of regimented training. The human body is very resilient and handles high levels of stress well in the short-term. When these stressors are properly managed, there is a positive adaptive response; in the case of a high resistance training volumes, the upshot is greater muscle growth. However, persistent exposure to such stressors ultimately overtaxes the body’s ability to respond, leading to an overtrained state. This raises the possibility that periodizing brief periods of higher volume with periods of lower to moderate volume training may be best for maximizing muscular gains.

In addition, we did not carry out testing at the midpoint of the study. It is possible that strength may have been greater for the higher volume condition after 4 weeks, and that subjects became overtrained thereafter so that results regressed. It also is possible that hypertrophy may have plateaued earlier in the study for the higher volume conditions and that continuing to train at high volumes were superfluous or even detrimental. These possibilities require further study. Interestingly, exit interviews with subjects did not indicate any perceptual signs of overtraining even in the highest volume group, although this does not preclude the prospect that it may have occurred.

It’s also important to note that we only measured hypertrophy in the arms and thighs. It remains to be determined if different muscle groups may have differing responses to varying amounts of volume. It seems likely that this would be the case, and that differential effects would be specific to individual genetics, whereby some muscles respond better to higher volumes of training while others don’t. There’s still a lot more to learn.

Take-Home Points

1. Strength gains are similar with 1 set per exercise as with 5 sets per exercise, indicating that if your goal is to simply get stronger, this can be achieved with minimal amounts of volume. These findings are specific to training with a moderate rep range (8-12 reps); it seems likely that training in more of a powerlifting range (3-5 reps) would necessitate the performance of more sets to maximize strength.

2. Volume is a primary driver of muscle growth, with more sets translating into greater gains. Upper body hypertrophy continued to show beneficial effects with 30 sets per muscle per week and continued lower body gains were seen with 45 sets per muscle week. These numbers should not necessarily be considered as definitive recommendations, but rather point to the fact that higher volumes can elicit superior muscle gains over relatively short time frames. Moreover, it seems likely that repeatedly training with high volumes will inevitably lead to non-functional overreaching and thus compromise results. Thus, volume should be manipulated in a wave-like manner so that periods of higher relative volumes are cycled with periods of lower volumes; moreover, regular deloads should be employed to promote proper recovery.

3. It’s essential to remember that studies merely provide the average responses to groups of people. Thus, these findings can only provide general guidelines as to how much volume is beneficial for strength and hypertrophy; the response for a given person will vary based on genetics and lifestyle factors and thus prescription must be determined individually. A good general recommendation for volume would be to perform ~10-20 sets/muscle/week, as detailed in our recent paper on the topic; some lifters will do well with volumes lower than this range, while others will thrive with somewhat higher volumes. The findings of our study suggest that specialized, short-term cycles of higher volume training can be employed to bring up lagging muscles groups that respond poorly to training or have reached a plateau in development.