A muscle growth fundamental that has been around for decades, and is lore in gyms across the world, is the concept of the ''hypertrophy rep range''. While it can be vague and changes slightly depending on who you talk to, it is essentially a moderate rep range thought to be optimal for growing muscle. It can be as low as 6 and goes to 15 at the higher end. The generally accepted rep range for building strength is thought to be 1-6 (roughly), and anything above 15 is believed to be endurance or something close to cardio.
Militancy about these rep ranges varies, with many stating that training outside of this range will produce minimal gains and is useless. In contrast, others use it as a general rule of thumb.
So where does the idea of the hypertrophy rep range come from and does it exist?
The Origins of ''The Hypertrophy Rep Range''
Where does the idea of these optimal rep ranges come from? For as long as gyms were a thing the idea that low reps are for strength and moderate reps are for muscle building has been floating around. Before science started delving into how to grow muscle, it was up to people to figure out what worked best themselves and these ideas likely sprang intuitively from self-experimentation and trail and error. Lifting heavy weight for reps seemed to build strength best, and moderate rep ranges somewhere between 6-15, seemed to be best for growing muscle.
Now that the science has sought to answer these questions more thoroughly, has it reached the same conclusions? The answer is kind of yes, kind of no.
The Science of Rep Ranges
A recent comprehensive review of research on the topic found that you can grow muscle with a wider variety of rep ranges (lower and higher) than the traditional ''hypertrophy rep range'' would suggest. Although this only reigns true if the volume is equated, its above 30% of 1RM (one rep max) and you are training close to failure. As long as you tick these boxes, you can theoretically gain the same amount of muscle in almost any rep range you choose. You may say this disproves the idea of the hypertrophy rep range and it kind of does. However, there are some practical limitations to low and high rep ranges that make the so-called ''hypertrophy rep range'' more attractive.
Low Reps, High Reps - The Pros and Cons
The evidence suggests that you can gain muscle performing a variety of rep ranges, but what are the pros and cons of low reps and high reps, respectively?
Pros and Cons of Higher Reps
Let's start with high reps. For higher reps to work for muscle growth, the volume has to be equated. Achieving the same volume lifting in higher rep ranges such as above 20 is far more difficult than lifting in the traditional 6-15 ''hypertrophy rep range''. With volume equated, doing all your training in higher rep ranges can leave you feeling sick (due to the metabolic stress that it creates), debilitatingly sore and exhausted. Not to mention the amount of time it takes. Another factor is training in higher rep ranges is less practical when it comes to certain lifts, especially large compound exercises such as squats and deadlifts. I can't imagine doing 25 rep deadlifts every workout.
That is not to say that higher reps don't have their benefits too. Higher reps are easier on your joints, and the metabolic stress generated by training in these rep ranges builds muscle and endurance in different ways than training heavier. Some exercises are better suited to higher reps, such as lateral raises for example. Higher reps have their place in training routines; they shouldn't be how you train exclusively.
Pros and Cons of Lower Reps
Now to lower reps. Training with lower reps, such as 2-4 is superior for gaining strength than say, training in moderate rep ranges like 10-12 reps. Gaining strength has great functional benefits, but it can also help you gain muscle, too. If you can gain strength, you can lift more weight, even when doing higher rep ranges which s means more volume and more muscle growth (hopefully).
The downside of training with heavier weight and lower reps is that it is hard on your body. Anyone who has ever done a heavy deadlift or session can attest to this. Another downside is that to match the volume required to grow muscle; you'd have to do a lot more sets with heavier weight, which means more time in the gym. All these factors and make workouts more physically and mentally exhausting. For these reasons, training with lower reps and heavyweight for every exercise and everyone workout is just not practical.
So, What is The Best Rep Range For Muscle Growth?
As mentioned previously, research shows that as long as you are equating volume, you can gain muscle using both high and low rep ranges (as long as you are using above 30% of 1RM and training close to failure). So what is the best rep range for gaining muscle?
Research shows that there is a relationship between more volume and muscle growth, meaning that the more volume you get through your training, the more muscle you will grow. This relationship is where the case for the hypertrophy rep range gets made. Sets performed close to failure in the 6-15 rep range are the most efficient way to accumulate volume in a training session. Doing the majority of your sets in this rep range will allow you to most effectively accumulate volume and gain muscle.
There is still value in doing low reps and high reps for the reasons mentioned earlier. Large compound lifts such as deadlifts and squats lend themselves better to lower reps and heavier weight. At the same time, higher reps and lighter weight is better for endurance and tends to be better for exercises like lateral raises.
A good rule of thumb is to use a variety of rep ranges in your training, for example, low reps for things like deadlifts, and higher reps for exercises like lateral raises. However, keeping the majority of them in the 6-15 rep range, training close to failure will allow you to most effectively accumulate volume and gain muscle.
-Bucky
