Picking Sets & Reps for Max Muscle Growth

How frustrating is it to see that skinny guy or gal at your gym out-lifting you?  I mean, they’re so much smaller, but lifting so much more. WTF?!?!?!?

If that doesn’t get under your skin, what about that other person you know that seems to put on muscle with ease, when doing the same is such a struggle for you?  

Grrrrrrrr!

Sure, some of these differences may be genetic, but the way you train has an enormous effect on your size and strength.

Think about it this way.  

The massive bodybuilders competing at Mr. Olympia aren’t also competing at the highest levels of powerlifting.  They have the most muscular and impressive physiques in the world, but are often far from the strongest lifters.  This is because their training is 100% focused on adding mass – strength is of much less concern, while top powerlifters flip those priorities around and are fixated on strength and strength alone (though some powerlifters do have good physiques too).

Picture from spotmebro.com article powerlifting vs. bodybuilding

This is a bit of an extreme example for everyday folks looking to get fit, but it still highlights the point that building strength and building muscle are often two DIFFERENT goals.

8-12 Reps… Duh!

Maybe you’re savvy to all of this.  After all, it’s “common gym knowledge” that 8-12 reps per lift is the magic range for building muscle.  But, is there really any truth to this or is it just gym lore? And, even if it is true, how many sets of 8-12 reps are required to maximally stimulate muscle growth?  

Let’s set the broscience aside and dig into what the scientific research actually has to say about optimal set and rep ranges for muscle growth.

How Many Sets?

To begin, let’s look at the results from a study that set out to determine if there is a dose response relationship between sets and muscle growth – this is just a fancy way of saying, do more sets always lead to more muscle?  To answer this question, they compared the size of the biceps and other elbow flexor muscles for lifters completing 1, 3 and 5 sets in their workouts.  

The group that did one set pretty much saw no change in size.  However, the group that did 3 sets saw some change. And maybe you predicted this, but the group that did 5 sets, well, they experienced the biggest change in arm size.

SetsStart Biceps SizeEnd Biceps SizeChange
13.6 cm3.7 cm+0.1 cm
33.5 cm3.8 cm+0.3 cm
53.5 cm4.1 cm+0.6 cm
*Training program was 3 days / wk for 6 months

 

Alright, so the more sets you do, the more gains you get, right?

Well, hold up there just a second professor.  You see, these types of studies are actually pretty difficult to conduct and extract meaningful results from.  Some use inexperienced lifters that respond to training differently than experienced lifters, some use different rep ranges and most use different movements and protocols – all of which can dramatically affect the response.  What we really need to understand are the trends across all (or most) of the studies.

In 2010 a meta analysis was conducted – basically a study of studies – looking for broader trends across all the research on the influence of sets on muscle growth.  These researchers concluded that 2-3 sets is superior to 1 set, but they found no real difference between 2-3 sets and 4-6 sets – though the authors of the study freely admitted the statistical power of their study was limited in the larger rep range.

Ok, so where does this leave us?  And while this discussion of sets is interesting, what about reps?  Is it meaningful to compare a study that did 3 sets of 8-12 reps with one that did 5 sets of 3-5 reps?

Pump Up The Volume

Instead of thinking in terms of sets and reps, maybe we should instead be looking at movement volume.  For the unacquainted, movement volume is simply the number of sets times the number of reps you perform in a session.  So, if you squatted a 5×5 yesterday, your squat volume for that sessions is 5 * 5 = 25 reps. And looking at training protocols this way enables us to make more relevant comparisons.  

Lucky for us too, another review study examined this exact training metric and found that the elbow flexors (biceps, etc.) of lifters that did 7-38 reps per session increased by 0.15%  / session. However, trainees that hit 42-66 reps / sessions experienced a 0.26% increase in elbow flexor size. That’s nearly double the gains!

Is this that same dose response thing we discussed earlier where more is always better though?

Actually, no.  The researchers also looked at data for lifters performing 74-120 reps per session and their bicep growth was much lower – only 0.18%.  That’s right, the lifters that did the most reps, got nearly the same results as those that did the fewest reps. These results highlight how it’s best to TRAIN SMARTER, NOT HARDER.

Muscle Cross Sectional Area Increase

Reps / MovementDaily Muscle Size IncreaseComment
7-380.15%Not doing much work
42-660.26%Booya!
74-1200.18%Whoopsie daisies

Now, why would the lifters that did the most reps not get the most gains?  It’s hard to say with 100% certainty, but most likely they were over-trained.  As with most things in life, when training, we’re looking for that goldilocks region – not too little, not too much… just the right amount; you know, the training volume that stimulates maximal growth without pushing so hard that you handicap your body’s ability to recover.  And according to this study, that appears to be between 42 and 66 reps per movement per session.

How you actually get those reps done is totally up to you.  You could squat for 10 sets of 5 or do 5 sets of 10. In the end, both result in 50 reps performed in a session.  In fact, it’s likely beneficial for you to mix up the sets and reps you perform in your training to maximize gains.  Maybe lift 5×10 for a few weeks and then switch over to 10×5 for a few weeks. There really is no magic rep range, total volume is what’s important.  

Additionally, when you change between 5×10 and 10×5 you’re also changing the % of your max you’re lifting with – because you don’t use the same weight for a set of 10 that you use for a set of 5, right? And that variation in load helps you stay on the gain train too – but that’s a topic for another day.

Finally, you may be wondering if you can spread those reps across different movements that target the same muscle group within a session.  For instance, can you do half barbell curls and half dumbbell curls? Or maybe half deadlifts and half RDLs? The answer is a resounding maybe.  Thus far, the scientific research has focused on doing the same movement. It’s reasonable to think two very similar movements can be used, but we simply don’t have the data to support that conclusion yet.  I will say, if you bore easily it’s probably best to mix up similar movements because it’s certainly more beneficial to stay engaged in your training than to half-ass it or skip it altogether.

What About Leg Day?

One final note.  Most of the studies highlighted above focused on the response of the elbow flexors to training.  This is largely an artifact of it being easier to conduct this type of research while focusing on that muscle group.  When reading studies in preparation for writing this article, I found there was much less evidence available on the response of the lower body to volume – though what I did find largely supported the conclusions highlighted above.  Shoot for 42 – 66 reps per movement per session and muscle growth will follow.

Let’s Wrap It Up

There really is no magic set or rep ranges for building muscle; the important metric to track is movement volume, which is the number of sets times the number of reps performed for a particular movement in your training session.

The research indicates that the ideal movement volume for stimulating muscle growth is between 42 and 66 reps / session.  How you break those reps up into sets is totally up to you: 5 x 10, 8 x 6, 42 x 1, etc. – all of these fall between 42 & 66.

Finally, the more is better mentality to building muscle is deeply flawed.  Doing too many reps in a session will lead to subpar results. It’s hard to believe that fewer reps can lead to more muscle, but if you don’t believe me, scroll back up and review Table 2 above that shows the gains of lifters based on reps / session.

Stay tuned for future articles on pretty much every other training variable you can think of, like: how many days you should lift per week, what percentages are best, which movements are ideal for each muscle group, etc.

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References

Dose-response of 1, 3, and 5 sets of resistance exercise on strength, local muscular endurance, and hypertrophy.

Radaelli R, Fleck SJ, Leite T, Leite RD, Pinto RS, Fernandes L, Simão R.

J Strength Cond Res. 2015 May;29(5):1349-58. doi: 10.1519/JSC.0000000000000758.

 

Single vs. multiple sets of resistance exercise for muscle hypertrophy: a meta-analysis.

Krieger JW.

J Strength Cond Res. 2010 Apr;24(4):1150-9. doi: 10.1519/JSC.0b013e3181d4d436. Review.

 

The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans.

Wernbom M, Augustsson J, Thomeé R.

Sports Med. 2007;37(3):225-64. Review.