The human body only puts on muscle when it feels it needs to, and it only feels this need when it finds itself in a situation where it is forced to work harder than it is used to in order to lift weight. The term “muscular hypertrophy” refers to the increase in size of individual muscle fibers, which in turn leads to bigger muscles and increased strength. Muscular hypertrophy occurs when muscles are put under stress, and the best way to stress out your muscles is through repetitive weight lifting exercises.
How many reps for hypertrophy? That depends. What you do need to be aware of if you want to gain muscle mass effectively is the principle of “progressive overload”:
In order to grow muscle, the human body has to be compelled to adapt to a level of strain that is increasing by increments all the time. To put it another way, if you spend the next decade lift the same weight with the same number of repetitions you will not see any results as far as muscle growth is concerned. You will only maintain your current physical state. However, if you increase the demands you are placing on your body by either increasing the amount of weight or lifting the same weight but increasing the number of repetitions, your body will have no other choice but to adapt accordingly to these changing circumstances.
An Example of Progressive Overload
Let’s say that you can bench press 220 lbs for 2 sets of 6 reps. Now, if you continue pushing the same 220 lbs with the same number of sets and repetitions you will not build muscle or increase strength. Your body will have simply adapted to this level of stress and strain, and will have accumulated the muscle mass necessary to handle this task on a regular basis. Given that you are not increasing the demand upon your body, you are giving it no reason to build more muscle; without any progressive overload over time, your body becomes complacent as far as muscle growth is concerned. However, if you bench press the same 220 pounds but add an extra repetition to each set (2 sets of 7 repetitions) than your body will be forced into a new situation where it has to build muscle.
While the improvement will be small, it will definitely be perceptible. Adding an additional repetition will have jolted your body out of its state of complacency. Likewise, if you stay with the same number of reps in each set but increase the weight that you bench press, than this is also progressive overload. For instance, you could stick with 2 sets of 6 reps but increase the weight on the barbell from 220 lbs to 240 lbs. Again, what you’re telling your body here is “hey! The job I’m giving you is getting a bit more strenuous, so I need you to build more muscle mass”.
So this is what progressive overload is, and it doesn’t matter if you’re adding an additional repetition to each exercise or adding 20 lbs of weight whilst doing the same number of sets and reps. The idea is to always be increasing the workload in your workouts so your body does not become to comfortable with your routine. Furthermore, the more frequently you ramp up your routines according to the principle of progressive overload, the more muscular hypertrophy you will see.
Does This Mean I have To Add Weight Or Reps Every Single Time I Work Out?
No! And frankly that is practically impossible. It it were the case that people could add more reps or weight to what they had been lifting at their previous workout than we’d routinely see just about everybody at the gym bench pressing 50 reps of 450 lbs. Obviously that is not the case, and you are not going to be able to add reps or weight every time you work out. Listen to what your body is telling you; biofeedback is your body’s way of telling you what it’s limits are, and if you do it you can end up injuring yourself and being sidelined for months.
Nonetheless, if you do want to build muscle mass, than the progressive overload approach that we’ve outlined here is the way to do it. If you feel like a given number of repetitions for a given weight for a given exercise is no longer a challenge, than it is time to step it up.