For the last decade or so, one of the most researched and talked about subjects in the area of resistance training has been volume. Specifically, how much volume optimizes your muscle growth?
A theme that has repeatedly come up in the research is that there’s a strong relationship between volume and your gains. But it appears that the volume and muscle growth relationship shows up in a U-shaped curve.
More volume builds more muscle, but only up to a point
Initially, when you add training volume (you do more sets and reps and exercises), you gain more muscle, but then as you keep doing more and more, the amount of gains tapers off. Ultimately, if volume goes over a certain level, your gains flatten out and reverse direction. That indicates you were overtraining and under-recovering.
Doing extremely high volume is also not time efficient. I mean, think about it. If you could get 95% of your possible gains doing 10 sets per muscle per week, and if you could get 5% more gains, but you had to do 20 sets per week, how many people would actually spend twice the time to do it? Probably only the most hardcore bodybuilders, not recreational lifters.
In the past, some people believed that the amount of weight used was the most important factor for muscle growth and that’s why they thought that heavy training was the best way to gain muscle. After years of research however, we’ve learned that this isn’t true. You can make similar muscle gains with low reps, medium reps and high reps, as long as the training volume is matched and you’re training intensely enough.
Volume load (tonnage) versus number of sets per week
Because training volume is such an important variable, athletes, coaches and scientists have been looking for a good way to quantify training volume. For a long time, the standard way to track volume was with volume load. That is simply the sets X reps X weight (in pounds or kilos). Back in the old days we called it tonnage. Today, volume load is the more common term.
A big advantage of tracking volume load is that it accounts for three different variables – the sets, reps, and weights. But a simpler method for quantifying volume has been proposed and is being used more often in recent years. That is, counting the number of sets you do per week.
With this in mind, a group of researchers (Baz-valle et al) recently did a systematic review of all the scientific literature on this subject to investigate this method (tracking sets per week).
The purpose of this study was to analyze different arrangements of sets, reps and training frequencies to see if the total number of sets is a valid metric to quantify training volume for hypertrophy training.
The researchers hypothesized that counting the total number of hard (near failure) sets could indeed be an alternative and easier quantification method for lifters who are training for hypertrophy.
There were 14 studies that met the inclusion criteria for this review. That included 352 men and 7 women, aged 19 to 35. A strong point of this review was that every subject had training experience.
Another strength of this review was that it analyzed four different types of studies:
1. Equal number of sets with different rep ranges.
2. Equal number of sets with different training frequencies.
3. Equal volume load with different number of sets.
4. Different number of sets and reps.
A big question they were looking to answer was whether the number of hard sets alone would produce similar muscle gains even if the total volume (volume load) was different.
What this latest research revealed
The results confirmed the hypothesis: counting the total number of hard sets is a good method to quantify volume and predict your muscle gain. But there were some conditions. The review said that total sets can be used to quantify volume if:
1. The number of reps per set is between 6 and 20.
2. Each set is taken close to failure (within 1 to 3 reps in reserve or at an RPE greater than or equal to 7).
First, let’s talk about reps. We know from previous research that you can gain an equal amount of muscle with heavy, low-rep training (3 to 5 reps) as you can with moderate training in the so-called “hypertrophy” rep range of 8 to 12 reps. You can even gain muscle with lighter training in the 15 to 20 rep range and higher.
However, if you train in the very low rep range (below 6 reps), you may need to do more sets to gain an equal amount of muscle. That is simply because heavy low rep sets, even though they stimulate the maximum number of muscle fibers right from the beginning of the set, don’t provide enough volume compared to sets with more reps.
When training really heavy with low reps (1 to 5), the number of sets is not a good way to predict hypertrophy. In this case, volume load would be better, and again, it will take more of the heavy sets to equalize the gains you would get with sets of 8, 12 or 15 reps. You might need 5 sets of 5 with the heavier weight to equal hypertrophy achieved from 3 sets of 8 to 10 with a moderate weight.
In addition, studies have showed that reps as high as 20 to 35 can produce muscle growth. However, it appears that the high-rep, low-load sets must be taken to failure to produce the same effect. A downside is training to failure on all sets might be counterproductive because it creates more muscle damage and increases recovery time. This could mean that weekly volume ends up lower. Extremely high reps are not as practical or time efficient either.
The researchers in this review concluded that if you want to use sets to quantify volume in hypertrophy training, the sets we should count are those that fall in the 6 to 20 rep range.
Looking at all the individual studies where not only the reps were in the 6 to 20 range, but also taken close to failure (1 to 3 reps in reserve), we see that regardless of what reps are used, muscle gains are similar when the same number of sets are done.
Practical application and conclusions
This was an interesting study with some major implications that may affect how you design your programs.
The main finding was that the total number of sets per muscle group taken close to muscle failure seems to be a reliable method to quantify training volume in experienced individuals who are training for muscle size gains. It’s also a simpler method as there’s no math to do as there is when calculating volume load.
This review also showed that other variables such as training frequency per muscle group, the weight used, and even the repetition range (excluding the repetition extremes) do not alter the results when the total number of sets are matched.
Regarding frequency, many experts today argue that a training frequency that works each muscle twice per week is better than a schedule where each muscle is worked only once per week. However, the difference is minor if each training program ends up with the same number of hard sets at the end of the week.
Regarding the repetitions and weight, it seems that if you use less weight, but you use higher reps (15 to 20), the higher volume of training produced by the reps times the weight is similar to using moderate weights for moderate reps (6 to 12). This may be a counterintuitive finding to people who have believed for years that using heavier weights builds bigger muscles. But this research says that the volume of training is the more important factor.
The intensity of effort is also an important variable for stimulating muscle growth. While sets that leave 4 or even 5 repetitions in reserve can still produce muscle growth, it doesn’t look like stopping this far short of failure stimulates as much growth as pushing closer to failure (within 1 to 3 reps). To build muscle at the optimal rate, the last few reps in a set need to be hard.
Training all the way to failure gives you assurance that the intensity of effort was high enough to produce growth. However, there’s a potential downside if you train to failure too often. Pushing too many sets to failure, especially on heavy compound exercises, can increase muscle damage, require more recovery time, and increase risk of overtraining.
There’s still strong support for using volume load as a metric to track volume. In fact, volume load takes into account 3 different factors (sets, reps and weight), not just weight alone, so it has advantages. For example, progressive overload on a specific exercise or on the entire session can be calculated down to the pound when using volume load. For this reason some people may use both numbers in program design and workout tracking.
A downside of volume load is that if you’re using it as a metric to track overload from workout to workout, the comparison must be made for the same exercise. You can’t track volume load for a squat in one workout and then compare it to the volume load for a leg press in the next workout and assume you achieved overload if the number is higher. They are totally different exercises (and you can always lift more on a leg press).
It’s the same thing with session volume load. If any exercises change in the workout, you can’t compare volume load to determine whether you overloaded. Similarly, you can’t compare the volume load of the current training program you’re doing now with a program you followed 6 months ago that had totally different reps and exercises.
But if you count the hard sets (between 6 to 20 reps), that can help you compare your workload in between different training blocks, track progressive overload and help predict whether a program will effectively build muscle.
The current volume guideline for optimizing muscle gains is to aim for between 10 to 20 hard sets per week per muscle group. Some experts have recently suggested narrowing this wide window down to 12 to 18 sets per week. Hit these volume benchmarks, work in the optimal rep ranges and push at least within a few reps of failure, and you can be assured you’ll be gaining muscle, regardless of weights and reps you choose.
These findings are incredibly useful because they reassure lifters and physique athletes that they can choose within a wide range of weights and rep ranges and still make gains.
If you have joint pain when training heavy, you can train in the 12, 15 or 20 rep range and still make gains if you hit the volume benchmarks and train hard and progressively in those rep ranges. (And make a note that working with lighter weights does not always mean easier – sometimes it’s more fatiguing).
Lifters who want to achieve maximum absolute strength can train mostly in the 3 to 5 rep range if they choose, they’ll simply have to do more sets to achieve an equal amount of hypertrophy along with the strength gains.
There’s still a lot of research going on looking at how close you should train to failure to optimize muscle growth. The current consensus is train close to failure, but leave a little bit in the tank most of the time. If you train all the way to failure on some sets, do it judiciously, keeping in mind how stressful that is and how it can increase muscle damage and recovery needs.
Though we don’t know everything yet, we have reached a point now where we have some excellent guidelines you can follow for volume. The best news is how this kind of research reveals the amount of flexibility you have in structuring your training according to your goals and preferences.
Train hard and expect success!
Tom Venuto, Author of Burn the Fat, Feed the Muscle Guide To Flexible Meal Planning
Founder and CEO, Burn the Fat Inner Circle,
The support community for all-natural no-BS body transformation
About Tom Venuto
Tom Venuto is a natural bodybuilding and fat loss expert. He is also a recipe creator specializing in fat-burning, muscle-building cooking. Tom is a former competitive bodybuilder and today works as a full-time fitness coach, writer, blogger, and author. In his spare time, he is an avid outdoor enthusiast and backpacker. His book, Burn The Fat, Feed The Muscle is an international bestseller, first as an ebook and now as a hardcover and audiobook. The Body Fat Solution, Tom’s book about emotional eating and long-term weight maintenance, was an Oprah Magazine and Men’s Fitness Magazine pick. Tom is also the founder of Burn The Fat Inner Circle – a fitness support community with over 52,000 members worldwide since 2006. Click here for membership details
Baz-Valle, et al. Total number of sets as a training volume quantification method for muscle hypertrophy: A systematic review. J Strength Cond Res 35(3): 870-878, 2021.