How many reps are optimal for promoting muscle growth?
It’s a question that is asked all the time. And there’s also much confusion over the issue. However, it CAN be answered.
While there is no magic number of reps, we can be sure that there is at least a RANGE within which our efforts produce the desired result i.e. increases in muscular size and strength.
For the purposes of this article we’ll be looking into the findings of the following 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.
How Many Reps To Build Muscle
So let’s not beat around the bush. What was the conclusion of this review….
~30-60 total reps per bodypart per workout is optimal for building muscle.
There are many ways to break this 30-60 reps down and I won’t go into them all.
Taking a look at THT Volume cycle, we can see that 5 to 6 sets of 8-12 reps-to-failure brings you in at 40 reps at the lowest, and 72 reps at the highest.
However, to get 72 reps you’d have to be hitting 12 reps on each of your 6 sets. The majority of MuscleHackers will perform 40-60 reps per body part the vast majority of the time.
In the HIT Cycle, we use a slower cadence which takes about double the time of a Volume cycle rep (about 7 seconds compared to 3 seconds). Our 7-10 HIT reps are more like 14-20 reps when you level out the “Time Under Load”.
Though this may be at the low end, we hit each body part 3 times per week in the HIT cycle. Furthermore, I provide concrete proof in the free book that such a method (1 set) DOES promote muscle growth on the condition that the set is brought to the point of momentary muscular failure.
Speaking of muscular failure, this paper goes on to say…
“Regarding intensity, moderately heavy loads seem to elicit the greatest gains for most categories of training, although examples of very high rates were noted at both very low and very high intensities when the sets were performed with maximum effort or taken to muscular failure.”
Basically this means that muscle growth can be seen using many different percentages of 1 rep max (1RM). From lighter sets and higher reps, and also low reps with a heavy weight. However, this is conditional upon taking those sets to failure.
A surprising example of this was the recent study “Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men“, which concluded that sets of just 30% of 1RM – that’s as high as 25 reps per set – produced better results than sets of 90% of 1RM in terms of protein synthesis levels.
However, this was also provided that these high-rep sets were done to failure.
Now, don’t rush out and change your workout straight away. This study didn’t measure protein accretion i.e. the net after subtracting protein breakdown from protein synthesis. Since the breakdown was almost certainly higher in the higher reps group, I think this might explain the findings.
I quote the study, however, to show the desirability of taking a set to failure. Those 30-60 reps can’t be done with just any weight. If you divide it up into 6 sets, you must select a weight that forces failure in all 6 sets (anywhere between 5 and 10 reps).
Someone out there is thinking, “Why not just do 2 sets of 30 reps? Or 1 set of 60 reps to failure?”
Here’s why I don’t think that’s an optimal choice…
You need to use a load above about 60% of your 1RM in order to recruit all the available motor units.
At 60% you’ll recruit them all after you’ve completed a few reps. If you go as low as 30% RM, those fast-twitch bodybuilding fibers will only come into play at the very end of a set.
Similarly, going too low and performing 1 or 2 reps to failure will use the 2b fibers predominantly. While we DO want to recruit these fibers, we definitely want to use our 2a fibers in every set when training for maximal hypertrophy.
If you take a set to failure in a moderate rep range, you’ll recruit your 2b fibers. But you’ll also recruit all the other fibers in the process. This is because muscle fibers are recruited sequentially (see this post for more).
When training in this manner, at the end of a set when muscle fibers are fatiguing, rate coding increases to help you keep producing the necessary force. “Rate coding” is simply the frequency of the signal that is sent to the motor units to contract. Increased coding means a higher frequency of signals.
It is for all these reasons that I named my training program Targeted Hypertrophy Training, which includes rep ranges from 5 (deadlifts) to 12, and will produce optimal muscle growth if you take those sets to failure.
So Get Out There & Train With 100% Intensity!
Mark
Great info mate. Thanks for sharing.
Downloaded your program last week, starting today!
Mark,
What’s your take on some in the industry who say it’s wrong to go to failure? Are they wrong? Are there any merits to it in your opinion?
Farley
Thanks Shane. And good luck on your journey!
@Shane. I disagree with that, as you might expect. They always seem to say the same thing, “It’ll fry your CNS”. It doesn’t. Must sound good though, they all use that exact same phrase.
The other argument is that if you go to failure, you can’t do a lot of volume. But it’s neither necessary nor desirable to “do a lot of volume” anyway – that’s a proven fact for natural bodybuilders.
Furthermore, increased volume can’t make up for a lack of intensity – Arthur Jones used to make that point and I totally agree.
sorry mark i wish u would make it more eh, plainer m8 i dont understand 2b and 1rm and so on !!speak english !!! as i and a lot off us aint got a clue what ur on about !! dont meen being funny or sarcastic seriously but its like reading a nasa program m8 !! cheers tho as u are always top notch all are best from plymouth
Mark,
another great article. I like your writing style and how it’s always backed up by scientific papers. Don’t let those other m8’s change you!
@mike 1rm is one rep maximum so its the heaviest weight you can move for one rep. 2b however is a part of a muscle strand, every muscle is made of different components each one is recruited sequentially so when one fatigues the next takes over. Marks programme aims to get every component of that muscle working.
when i first started researching i somehow stumbled across Marks site and im SO glad i did (ive been stuck at 78kg for 3 years, working on marks advice in 10 weeks im up to 82.5kg with no extra fat 🙂 ) i was dubious at first and read through essentially every archive on this site and learnt so much, most of all the info has been covered in previous posts, I really recommend when you have time, have a read through them, the knowledge shared is invaluable (bare in mind there are ALOT of posts so you can easily lose an evening…weekend)
Thank you Mark for being the student and scientist in these matters.
@mike. I had no idea the article read like that. Apologies for the jargon. I always make the assumption (right or wrong) that the reader will have read my previous articles and will be familiar with the terms.
@Grant.Thanks very much man.
@Mark C. Congrats on the muscle gains! Sorry for taking up your weekends 😉
@John. You’re welcome
I agree with Mark C. in regards to mikes comment. Do take the time to read back thru Mark’s wealth of posts and training programs. It is all simply explained for ya. I had trouble gaining muscle mass for years. Been with Mark since March and have gone from 197lbs. to 210lbs. and i’m 42 years old. Your Incredible Mr. McManus!! Thanks A Bunch Mark!!
Mike Huber
@Mark M, couldnt of gained without ya, taking up my weekends…? you my friend have given me my weekends back! before i was training 2-3hrs a day 5 days a week, got kinda toned and gained no weight, I thank you again for giving me my weekends back as well some extra meat on my skinny frame 🙂 I look forward to starting the TA 3.1 5 day cycle in a coupla weeks
@Mark M, if you train to muscular failure for every set, how are you supposed to move up in weight every set? because i was taught that you must move up some weight in each set to promote the ripping of the muscles for growth? is that not right?
Great article Mark. Every time I need a boost, like magic there is an article to explain how it all works. Keep up the good work and thanks for the motivation!!!!!
@Mike Huber. My pleasure, man. Congrats on your success!
@Mark C. Awesome! Yeah that over-training will seriously rob you of your time, not to mention ensure that you don’t make any progress. You’ll enjoy the THT 5-day plan.
@Doug. That’s definitely not the way to go. If you are adding weight in successive sets, it means that your previous sets obviously didn’t push you to 100% intensity.
If you did 10 sets, and only use your heaviest weight in a given rep range in that 10th set, the previous 9 sets were a waste of time (or a warm-up at best). What was the purpose of the first 9 sets?
You must start out at the top and literally be forced to decrease the load in successive sets because you are continually making INROADS into your strength with every set. This is sometimes called a ‘Reverse Pyramid’ approach and is central to THT training.
Making these inroads is the THREAT signal that you must send to your body in order for it to respond by building more muscle. Always remember that muscle growth is a DEFENSE mechanism by the body, in the same way that scar tissue is.
Now, I actually have written an article that explains this very well. It’ll only take a couple of minutes to read and will end your confusion…
https://musclehack.com/the-best-way-to-gain-muscle-mass/
@Andrew K. Glad to be of service!
I have to say this is pretty profound stuff you got here. It seems a bit intense, but I guess if a person just follows closely then they will get it. I have heard word for and against training to failure.
One thing i know for sure is you can get just as good a workout from high intensity routines for 35 to 45 minutes. Then you would doing a 2 hour routine of medium or low intensity activities. If done right.