The muscle building rep range is hallowed ground for anyone looking to get jacked. If you want to get bigger that coveted 8-12 reps is home base for your workouts. Heaven knows I’ve spent most of my time there, and the results have been great.
Lately, I’ve been putting some pieces together and it’s making me question if the existence of a muscle building rep range. In fact, you may be holding your gains in check by focusing too much on that narrow rep range.
Let me explain.
Muscle building and the rep range spectrum
Experts have long known about the rep range spectrum. (RRS) It shows the inverse relationship between the only two variables you can manipulate within a muscle; time and tension.
The RRS shows the relationship between time and tension. On one side you have a high level of tension which you can hold for a short period of time. On the other end, you have less tension which you can hold for longer periods of time. This relationship is helpful for programming your workouts to your specific goals. As I mention in my book, Fitness Independence, the S.A.I.D principle states that you gain that which you challenge. So if you want to get stroner, you use the range of the spectrum that challenges your strength (ie a greater amount of tension in your muscles.) If you want endurance then you use the end of the spectrum that challenges your stamina (ie. time you hold tension for.)
The theory of having a muscle building rep range states that the middle ground is where you build the most muscle. Where as the zone on the left is for building strength, the zone on the right is for building endurance and the zone in the middle is for building muscle.
These zones are very handy for programming your workouts, but the popular understanding of it has become skewed over time. One such example of this is the belief that you only develop that physical result when you train within that repetition zone. For example, if you lift for 1-5 reps you only build strength, but not muscle or endurance. If you lift in the hypertrophy zone then you only build muscle but not strength or endurance. And if you lift above 12-15 reps then you only build endurance but no muscle or strength.
This misguided belief is also coupled by the notion that each zone is separated by one or two reps. So if you lift for 12 reps then you build muscle, but if you lift for 14 you won’t build any muscle and only build endurance.
The myth isn’t that you can emphasize different aspects of your training depending on your rep range, you can. The myth is that each of these zones is exclusive to developing just one outcome.
The truth is, you always develop both strength and endurance regardless of what rep range you use. This is because all exercises use some degree of tension (strength) for some period of time (endurance.) The only difference between moving from lifting heavy or light is which aspect of tension are you emphasizing.
Why the muscle building rep range is made up
At first glance, it might seem like the SSR has three zones (strength, hypertrophy, and endurance) but there are actually only two. Once again, remember, your muscles only understand time and tension. Second, they also only understand functional demand. So all forms of training tell your muscles to use a balanced combination of tension and time for the single purpose of being able to do the job you want them to do. This means that no matter what sort of exercise you do, all your muscles understand is how you’re trying to use time and tension to be able to do the exercise. There is no such thing as a way to directly tell your muscles to get bigger. The body only cares about being able to meet the functional demands of your mind. You cannot instruct your body to look a different way. Sitting on a weight machine or using an elliptical doesn’t tell your muscles to be bigger, leaner, more toned or more shapely. All your muscles understand is how you’re using time and tension to get something done.
But how do you explain body builders?
Even though we can’t directly tell our muscles to get bigger with a specific rep range that doesn’t mean we can’t make them bigger indirectly. We believe there’s a hypertrophy zone because various studies over the years have shown that’s where subjects build the most muscle.
The mistake isn’t in believing there’s a hypertrophy zone. The mistake is in failing to consider why that was ideal for that study.
So far as I’ve been able to tell, our muscles get bigger when we increase its functional capacity in both strength (how much tension) and endurance (how long the tension lasts.) Working in that middle ground gives the best short term results because it’s a mix of both strength and endurance.
So the supposed hypertrophy zone is a great place to build muscle because it does a great job at challenging both the strength and endurance of a muscle. The question is, should you confine yourself to it? Absolutely not. You build bigger muscles by improving both your strength and your endurance. Focusing too much in one area or the other can short-change your results. Focusing on strength is great, but failing to push the endurance of the muscle will not sufficiently deplete the chemical energy within the cells thus stimulating much growth. Training for endurance is also great, but if you never get stronger you won’t recruit as many muscle fibers at a time and fail to use as much chemical energy yet again. Either way, you’re not using as much of the functional capability of the muscle by focusing in one rep range.
This is why guys who used to always focus on endurance (like doing 500 push-ups a day) find they spark new muscle growth when they add resistance to their training. At the same time, guys who focus on exercises that use a lot of strength stimulate new growth when they include some higher rep training in their program. This isn’t to say that you don’t build muscle by focusing on strength or endurance. Remember, all exercise use both strength and endurance so all exercise builds muscle to some degree. The trick is to utilize more of the RRS so you build as much strength and endurance as possible to fully build the functional capacity of the muscle and therefore its size. So it’s not so much that the muscle building rep range doesn’t exist, it does. It just exists along a much wider rep range than thought. You’ll build more muscle through challenging both your strength and endurance over time.
This is why periodization can be helpful where you focus on building either strength or endurance at a time. You can also alternate heavy and light workouts from workout to workout, week to week and month to month. The basic idea is if you use a much broader rep range you build the total strength and endurance and therefore the total muscle mass.