How can you really gain muscle mass? A hypertrophy expert shares some advice

Forget about infinite repetitions: the most important thing, according to author Brad Schoenfeld, is that the exercises are performed with a high degree of effort

Mujer con pesas
A woman trains with dumbbells at the gym.
Sara Tabares

Simple matters, such as getting up from a chair, going up the stairs and taking a walk, or other, more complex ones, like exploring a new city, climbing a mountain or jumping on a trampoline with your child, may sound doable to you, but for some people these actions are impossible, as they lack the proper neuromuscular conditioning. Muscle mass is your life insurance; with it, you will fend off fragility and have health, independence and autonomy. However, it is important to avoid focusing only on how your muscles look and neglecting functionality; what you don’t use, you lose. This is how your neuromuscular system works.

The term “muscle hypertrophy” refers to the growth of muscle tissue, which can manifest through a variety of structural and metabolic adaptations. Maintaining muscle mass requires a higher caloric expenditure; if you stop training, your body will notice that you are not using those tissues and will take it as a waste of energy, launching certain mechanisms to get rid of that excess. The result can be a loss of muscle mass.

Strength training helps you prevent this as you optimize the functioning of your entire neuromuscular system. But why is it important to maintain and gain muscle mass? According to studies, having little or no muscle mass is associated with an increase in several cardiovascular diseases and cardiometabolic risk, as well as type II diabetes in middle-aged adults and a loss of functionality in older adults.

After reading the phrase “the iron became my savior” in The M.A.X. Muscle Plan 2.0 by researcher Brad Schoenfeld, expert in hypertrophy, I realized that not everybody knows what actually works to achieve the goal of gaining muscle mass.

The myth of infinite repetitions and low weights

There are different factors that affect the development of muscle mass. Schoenfeld’s most recent work states that there is no specific number of repetitions to gain muscle mass, and explains that different ranges and intensities can lead to similar levels of hypertrophy. Many years ago, working with infinite repetitions with a high volume and low weights was thought to be the right formula; however, that has become a thing of the past, defeated, once again, by scientific knowledge. This is why, after reading the book, I decided to have a chat with the expert.

The three key factors for gaining muscle mass, according to Schoenfeld, are:

Mechanical tension

This refers to the stress exerted applied to a muscle during an exercise. The higher the mechanical stress, the closer you get to muscle failure. Could staying close to it be the crucial aspect? It is, he confirms. “Similar hypertrophy can be achieved over a wide spectrum of load ranges (up to 30 or more reps per set). The key is that the training is carried out with a high degree of effort, in which the last repetitions entail a considerable challenge for the muscles,” he explains. Of the three variables, Schoenfeld points out that the most decisive is mechanical tension. “If we don’t generate enough, the other mechanisms will have a limited effect.”

From theory to practice: muscle growth is very similar regardless of the repetitions you do, as long as the series are done with a high degree of effort. That would imply, in practical terms, completing the last repetitions when it becomes harder. The overload principle — training by subjecting your body to a stress or intensity greater than what you are used to — is the key. When designing a workout, you should be clear that you are going to gain muscle mass regardless of the number of repetitions; the determining factor will be the degree of effort.

Metabolic stress

To generate metabolites is to achieve muscle congestion. In his book, Schoenfeld points out that exercise-induced metabolic stress is “perhaps the most intriguing factor associated with muscle development.” He explains: “The muscle-building effects of metabolic stress can be attributed to the production of by-products of metabolism called metabolites. These small fragments (including lactate, hydrogen ion, and inorganic phosphate) indirectly mediate cell signaling.” Metabolic stress increases when you train with moderate to high reps; if you feel the burn when pumping a set of 15 reps, it is due to the buildup of local metabolites (lactic acid). Some research has shown that cell inflammation stimulates protein synthesis while reducing protein breakdown. Schoenfeld writes: “It is not clear exactly why cell swelling causes an anabolic effect, but the prevailing theory suggests a self-preservation mechanism. That is, an increase in water within the cell exerts pressure against the cell wall, similar to overinflating a rubber tire. The cell, in turn, perceives this as a threat to its integrity and responds by sending out anabolic signals that initiate strengthening of its ultrastructure.”

Muscle damage

Have you noticed a feeling of discomfort after an intense training session? This can be similar to the acute inflammatory response to infection. Once the body perceives the damage, certain cells of the immune system migrate to the damaged tissue in order to eliminate waste and preserve healthy muscle fiber tissue. The pain you feel should not be an indication that you are doing better. When we train regularly, adaptations are generated and the muscles become more efficient. The key here is in individualization. Find the optimal dose for each one, in which the damage entails a challenge that benefits them, instead of an overload that harms them.

When it comes to gaining muscle mass, there are many possible mistakes. The most common, according to Schoenfeld, is following the program of a bodybuilder, a celebrity or an influencer; what works for one person may not necessarily work for another, so the program must be customized to optimize the results.

Programming should be similar in men and women

According to the journal The Lancet, women tend to have more frequent and serious problems, such as sarcopenia (loss of muscle mass, strength and function), frailty and disability. This is why hypertrophy should be a goal for all women. Schoenfeld stresses that, generally speaking, programming for both sexes should be similar; women tend to have a better recovery capacity, so they may benefit from slightly shorter rest periods and could train more frequently.

The selection of exercises can be a variable to take into account when organizing the training. Multijoint and single-joint movements are synergistic in a hypertrophy-oriented program, and a combination of both is beneficial for maximum gains. The key is to observe the biomechanical implications of each movement in order to make decisions based on which exercises are most appropriate for each person.

Warm-up, or activation? That is the question

Many users want to train more effectively and efficiently, which often translates into saving time. But, what to do? When should you work on mobility? Only when you notice stiffness in a joint? Is it enough to use the first set of each exercise as warm-up? The expert recommends taking a self-regulatory approach: assess how you feel after a warm-up set, and if you think you need one or two more, go for it.

After so many years of research, Schoenfeld sums up the key to training and gaining muscle in one word: consistency. While other factors might be extremely relevant, without consistency, he points out, the desired results simply cannot be achieved. To this, we agree; the best exercise is the one you do. Living involves moving, training, using your muscles to avoid losing them.

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