We all have our reason to get more jacked. Maybe you want to look better naked, because you watched Conan the Barbarian, lift heavy things because being strong is cool and useful, or maybe you simply want to be more healthy. All these reasons might motivate you to start resistance training to get jacked. In this article, we will talk about what causes muscle growth so you can get as best results possible.
what causes muscle growth?
How do we send the signal that our bodies need to build muscle? There are usually three referred to leading causes of hypertrophy stimuli.
- Muscle tension
- Metabolic stress
- Muscle damage
Muscle tension will be the main cause of muscle growth in most training. This is what is caused when your muscles produce force and what happens in most straight sets in training. As the reps are taken closer to failure more muscle fibers are recruited to produce force and this sends a stimulus for the muscle to adapt to the stress.
Metabolic stress is caused by the build-up of metabolites in the muscle. This is caused by fatiguing the muscle and happens during higher rep sets with shorter rest times. This is often the goal of intensity techniques such as blood flow restriction, myoreps, or supersets.
Often muscle damage is also mentioned as a cause of hypertrophy, but it's not clear that the relationship is causal and not just a correlation.
How hard should you train to grow muscle mass?
We now know that the goal of training should be to create muscle tension and metabolic stress through exercise. But this can mean many things, should you work up a light sweat or should each set be taken to post-failure death?
Most people would intuitively think that the harder you work the better gains you make. This naturally leads to the conclusion that you should take everything to failure. This of course has the advantage that you always know when you are done with the set. For many reasons, this isn't very practical. mainly because you are not going to do it. Training to failure is very taxing, both mentally and for your body. It also turns out from research that taking a set 1-3 reps from failure gives just as good results as actually going to failure.
We recommend that you do compound lifts at RPE 7-9 and rarely visit failure and isolation work at RPE 7-10. In a four-week mesocycle, this could be done by taking sets to RPE 6-7 the first week. Then, in the following week, you increase the RPE by 1 each week until the lifts are at RPE 9-10 the last week.
How many reps should you do to build muscle mass?
How many reps should you do to build muscle mass? In the olden days, people spoke about a hypertrophy rep range, a strength rep range, and so on. However today we know that this isn't a thing. We now know that reps from 1-30 reps or 30%-100% of 1RM can build muscle mass if taken close enough to failure. However, not all rep ranges are equally efficient at building muscle. Since reps in the 1-4 probably come at a stimuli-to-fatigue ratio that isn't favorable to building muscle. We thus recommend that one stay within the 5-30 rep range. Here most training should probably be done in the 5-10 and 10-20 rep range. Since it's hard, to be honest about RPE in a 30-rep set. (Was this muscular failure or was the burn just too much?)
How many reps one should do for an exercise highly depends on the exercise. Some exercises might fit in multiple rep ranges, while others not so much. For example, doing squats or deadlifts usually fits best in the 5-10 rep range, unless one has a particular self-hatred. Usually, these exercises tend to just burn out the lower back at high reps, while maybe not working the muscles one wants to tax very much.
Other exercises, like lateral raises, might not be so great at lower reps. While they might work great at higher reps or done with intensity techniques, such as myoreps. In general compound movements, where heavy weight can be lifted, lower rep ranges work well. While isolation and machines, work better at higher rep ranges.
How often should you train to build muscle mass?
We now know we stimulate muscles and how hard we should train them. But how much should we train and does how often we train matter? A few years ago the answer would have been clear. The gym bro would tell you to train your muscles once a week in a body part split, also known as a bro split. A more sciency person would tell you to at least hit each body part twice a week because something about muscle nucleosynthesis only being elevated for 24-48 hours after working out.
However, more recently it turns out that this might not be so true after all. First, it was discovered that thrice a week frequency did not produce better results than twice a week. It has since turned out that training twice a week might not be better than once a week. What turns out to matter is the total weekly volume. So in essence higher frequency will only help your hypertrophy gains, if it allows you to do more volume of a higher quality. But increasing volume and quality also come at a higher fatigue cost. So for the very strong or for larger muscle groups, lower frequency might sometimes be a better choice than higher frequencies.
How many sets should you do to build muscle mass?
How much training volume an individual can take varies widely. Some people might be very sensitive to training and can only handle very little training. This is often people who are big and very strong. While others might be able to tolerate large amounts of volume, often people who are weaker and lighter.
A general recommendation of where to start would be 10-20 weekly sets per muscle group. Again depending on the individual, the muscle group, and of course RPE, this number could be both much lower and much higher. If a training cycle is done in a more periodized manner. Where one split training up into mesocycles. In the first microcycle, one could start with whatever number of sets it takes to get a pump and some light disruption. Then over the week as one adapts to the volume more sets, reps and weight is added. After a capacity to adapt to training has been reached, usually due to accumulated fatigue, one deloads and starts over.
About Rasmus Skriver
Powerlifter and coach with more than 7 years in the game.