Select your country
Select your country
What determines muscle mass: genes, training or nutrition?

Your genetic background is important and determines your physical capacities and limitations.But how you exercise and what you eat interacts with your genes. The rate of muscle growth can be improved by your lifestyle, but wrong or bad nutrition or inadequate training programs can have the opposite effect and reduce lean mass.

Muscle growth is not only the result of training the muscle fibres. It involves many biological pathways that are necessary to support an increase in muscle mass.


Here are just a few processes in the body, all with a genetic component, that influence your ability to gain lean muscle:

  • Muscle type composition (slow twitch and fast twitch muscle fibers)
  • Flexibility of joints and muscles
  • Resistance of tendons and ligaments
  • Lung capacity
  • Heart capacity
  • Oxygen absorption capacity
  • Metabolic capacity, use of sugar and fatty acids for energy
  • Recovery after training thanks to antioxidant and detoxification reactions
  • Pain perception
  • Heat dissipation

You can be born with few or many genetic limitations that allow you to develop muscles more or less easy. But exercise and food can make a big difference:

By adjusting your exercise program to your genetic profile, you can focus on stimulating the weakest biological pathways to increase overall performance. Genetic analysis reveals how your training should be organized to obtain maximum benefits.

Nutrition is another equally important factor for muscle growth. Although muscle building forums are overflowing with advice on what to take and how much, the truth is that there is no golden rule. Just like our muscle type, our ability to digest, absorb, and metabolize certain types of food and vitamins is determined by our genes, and it is different for everyone. For example, the RVDs (daily recommended values) for the consumption of vitamins, as established by the FDA, represent an average amount that must be consumed by the majority (97%) of the population. But 3% of the population fall into a category where this amount is either too high or too low.

For these people, consuming the recommended values can make them sick or weak. In other words: a daily intake of vitamins that is considered “normal” can be harmful to you and can affect your health and performance. Now that genetic analysis is becoming more and more popular and we get a better overview of global genetic variations, we realize that nutrition is a personal choice and the old-style general dietary recommendations do not guarantee that you get the right nutrients to build your muscles. A genetic test shows you which nutrients you need to take the most and which ones to avoid, so that your muscle building capacity works at an optimal speed.

Personalized nutrition is already a general practice in elite sports. It aims to optimize health, body composition and physical performance by adjusting dietary recommendations to the genetic profile of the athlete. But the benefits of genetically adapted nutrition are not limited to elite athletes! Anyone can improve their health and fitness through personalized nutrition. The cost of genetic testing has dropped, making it accessible to most of the world’s population. In addition, small-scale manufacturing allows the development of tailor-made food supplements that include the right combination of ingredients to meet individual needs.

Dr. Sonia Van Kerckhoven

PhD in Cellular and Molecular Biology

MSc Expert in Nutrition

Expert in Medical Genetics