The Most Effective Amount of Reps for Muscle Growth

When it comes to training, most people are looking for absolute clear-cut answers when they ask a question.  Whether it’s regarding how much cardio is necessary, how many sets/reps they should do, or if they should just bail on training all together and seek the help of a plastic surgeon, there is never an easy answer.

Unless the question falls into the waist trainer, juice cleanse, or elevation mask category of moronic, 99.9% of the time the answer is going to be “it depends”, and then require more questioning to determine other variables such as goals, injury history, training experience, current frequency, and blah blah blah, you get the point.  One of the more heavily debated areas of exercise science that causes fitness pros to butt heads is the topic of resistance training rep ranges. 

   Elevation masks started poppping up more frequently when Creed wore one.  There are zero advantages to wearing an elevation mask outside of looking cool, making them perfect for a training scene in a Rocky movie but pointless for you and I.   Click here to learn why.

Elevation masks started poppping up more frequently when Creed wore one.  There are zero advantages to wearing an elevation mask outside of looking cool, making them perfect for a training scene in a Rocky movie but pointless for you and I.  Click here to learn why.

It’s been a long-held belief that training in the rep range of 1-5 makes muscles strong, 6-12 makes muscles bigger, and 15-20 increases endurance.  This concept is called the “strength-endurance continuum” (SEC) and was a major part of the program design chapter for my NSCA CSCS certification and my Exercise Science program in college.  It’s important to note, I graduated in 2004 and got my CSCS in 2005.  I have no clue what they are teaching now, I’m guessing the curriculum is quite different. 

In applying this heavily regarded truth, if one has the yearning to look better naked or walk around jacked, then one must stick to 6-12 reps per set on all exercises with no deviation for their entire training life.  While this seems logical given the “hypertrophy zone” of 6-12 reps, thanks to a few key studies, it may be in every lifter’s best interest to reevaluate their rep ranges.  If you're one of those that have been married to 3 sets of 10 reps on every exercise since the first day you benched an empty barbell, it’s time to upgrade. 

Go Heavy or Go Home

The biggest fallacy of the SEC is that heavy weights for low reps don’t build muscle size.  It only takes one look at a heavyweight powerlifter to know that is B.S. as they are some of the most muscular athletes that exist.  While they focus primarily on building strength, that doesn’t mean hypertrophy doesn’t occur.  Strength and hypertrophy work hand in hand.  What do you think produces more force, a big muscle or small one?  Powerlifters primarily use big weights for low reps for their main lifts.  Some of the biggest and strongest people on the planet literally will never perform a set over 5 reps for months at a time as they refer to anything higher than that “cardio”. 

 Pictured is Ed Coan, one of the strongest power lifters of all time, he's also jacked.  Coincidence? Doubtful.  

Pictured is Ed Coan, one of the strongest power lifters of all time, he's also jacked.  Coincidence? Doubtful.  

In a study by Campos et al. 32 resistance trained men were studied to shed some light on the legitimacy of the SEC.  The subjects were divided into 3 groups, a low rep group (3-5 reps), intermediate rep group (9-11 reps) and high rep group (20-28 reps).  Muscle strength (1 rep max) and size (via muscle biopsy) were both assessed pre and post study.  After 8 weeks of training in their respective rep ranges, the low rep and intermediate rep groups each responded with almost the exact same muscle growth!  The edge in strength however went to the low rep group, crowning them as the most efficient group of the study.  It looks like the line between strength and hypertrophy in terms of amount of reps performed isn’t as clear as was once thought. 

While the argument can be made that frequent heavy lifting in low rep ranges would be more efficient due to the gains in strength and size, in practice there comes a point of diminished returns.  Going heavy too often will eventually wear down your joints and tax your central nervous system, either one of these issues will put a serious dent in your ability to make progress in the gym.  Go heavier with low reps for compound movements (squats, deadlifts, rows, presses) for limited periods throughout the year to get the most out of your training without risking injury. 

High (and intense) Reps for Hypertrophy

Training with high reps as it pertains to this article is using high reps either to failure or close to it.  If you aren’t feeling significant muscle fatigue and blood flow in the targeted muscle, you’re doing it wrong.  High reps hurt, flinging around a dumbbell while tweeting or snapchatting doesn’t count.  Somewhere along the way, in the general population, training at high reps became muscle “toning”.  I’ve written about this before and I still literally have no idea where that came from.  Your muscles are either getting bigger, smaller, or staying the same size.  Your body fat is either increasing, decreasing or staying the same.  For a muscle to become more “toned” it must increase in size (hypertrophy) or body fat must be lost, even better is a combination of both. 

   Not sure of the exercise here, but I can safely say no matter how many reps are performed, nothing is getting "toned" as a result of this.

Not sure of the exercise here, but I can safely say no matter how many reps are performed, nothing is getting "toned" as a result of this.

According to the SEC, high rep training will increase muscular endurance however fall short of promoting muscle hypertrophy.  In 2012, a study by Mitchel et al. proved differently.  In this study, the subjects were split into a high rep group (30% of 1 RM) and a low rep group (80% of 1 RM) and instructed to do 3 sets to muscular fatigue.  Over 10 weeks of training, both groups had nearly identical increases in hypertrophy of the targeted muscle.  The muscles responded with growth regardless of high or low rep!

Using high reps may not increase 1 rep max strength anywhere near as much as lower reps but it will still stimulate muscle growth.  High reps are a great tool specifically on single joint exercises like bicep curls and leg extensions to give the joints a break from heavy loads, increase mind-muscle connection, and get a nasty pump in the targeted muscle.  

Application and Take Home Message

As science would have it, our muscles don’t seem to care how many reps it takes to get to muscle fatigue or failure, hit them with enough intensity on a consistent basis and they will grow.  Training exclusively high or low rep has its drawbacks.  Too heavy (5 reps or less) for too long and you risk overtraining, joint stress, or lack of muscular endurance.  Training in higher rep ranges (15+) for too long and strength progress will stall.  Performing a varied amount of rep ranges over the course of a training year seems like the best approach when all the variables are considered.             

Are your workouts getting you the results you want?  Do you feel like they are efficient enough? Are you maximizing your precious time in the gym? If not, click the button below and head over to my custom programming page to learn how you can get a made-from-scratch program to get you where you want to be!