Genetics is the field of science that explains genes and how traits are passed from parents to children through changes in the DNA sequence. The human genome is the complete set of genetic instructions in a person's DNA. All cells in the body have their genome, which represents the cell nucleus.
A DNA is a molecule that contains instructions for building other molecules that help our body function. A gene is a piece of DNA that contains instructions for building a specific protein. Proteins are molecules that perform various tasks in our body such as triggering chemical reactions, fighting diseases, controlling cell growth, etc.
The physical characteristics that an individual carries are influenced by their genes. For example, hair color, eye color, skin color, height, body type, etc. Although we cannot change most of our physical characteristics, some can be changed as they are also influenced by the external environment e.g. E.g. weight, muscle mass, even to some extent height and skin color.
There is simply no argument that genes play a crucial role in a person's athletic success. Your genetic makeup may make you naturally better at strength, speed, or endurance sports.
The very first principle of exercise physiology, on which the entire range of physical activity is based, is the “Principle of Individuality'.
This simply means that we are all born different, with different genetic characteristics and unique abilities and needs.
Many factors present at birth play a role in building muscle and demonstrating strength. Limb length, tendon insertions, fiber composition, muscle belly length, initial hormone levels, and neurological factors are all inherited.
For this reason, every individual reacts differently to the same training. For example, a group of athletes looking to build muscle and strength might all follow the same well-designed program, nutritional protocol, rest and recovery program, but upon completion the individual training response could vary greatly between athletes. Some will have gained more muscle, some will gain a lot of weight, some will gain a little weight, and some may not be able to complete the program.
In a study where strength athletes trained their quadriceps for 16 weeks, a quarter of them increased their quadriceps size by 58%. Another quarter of trainees experienced no size gains at all, and the majority of participants increased quadriceps size by 32%. When the study authors took a biopsy of exercisers' quadriceps, they found that the relative number of specialized stem cells, called satellite cells, in the muscles predicted how well their muscles would grow in response to exercise.
In a study, gender differences in size and changes in strength after training were examined in 585 subjects (342 women, 243 men). The study showed that 12 weeks of progressive resistance training resulted in different responses, with some subjects showing little or no progress while others showed profound changes.
Size changes ranged from -2 to +59%, 1RM strength gains ranged from 0 to +250%, and MVC changes ranged from -32 to +149%, despite following the exact same training protocol.
– Another important indicator of how much muscle you can build is the size of your muscle belly and tendon. The muscle belly is the main muscle we are talking about, and the tendon is the one that connects the muscle to the bones.
The size of your muscle belly and tendon is genetically defined. You were born with it. Some people have longer muscle bellies, others have short ones. Likewise, some have longer tendons and others have shorter ones.
Because of your genes, you can't grow your muscles any longer. You can only make them grow wider. So if you are born with longer muscle bellies and shorter tendons, you would gain much more muscle mass than the person with shorter muscle bellies and longer tendons.
However, that would only matter if you actually put in the effort to get taller. A person with a shorter muscle belly and a longer tendon will overtake the best genes in the world if the other person is not interested in growing them to greater proportions.
– The composition of your muscle fibers is also genetically determined and contributes significantly to how tall you can become. There is a famous saying that a marathon champion doesn't look the way he does because he runs marathons. He runs marathons because he was born that way. This applies to all the top long-distance runners in the world.
Look at the athletes from Kenya and Ethiopia. The reason why they dominate the sport is because of their excellent genes, which serve to give an edge to the other athletes around the world. Not that you can't beat them with a little practice, but the chances are slim. The statistics show this clearly. Take out the results of all the short sprint and long distance runners at the Olympics or World Championships and see how many are black.
Likewise, people with faster-twitch muscle fibers have greater potential for size and strength. Those with more slow-twitch fibers have greater endurance potential. This is something you cannot control. It's what you're born with.
To check the composition of your muscle fibers, you would have to have a biopsy done for each muscle, which would be impractical from both a financial and sporting perspective. If you are interested in becoming an athlete, it will be obvious from a young age what sport you excel at. This is where the role of the coach comes into play.
For example, a gene that strongly influences an individual's muscle fiber development is the ACTN3 gene. The ACTN3 gene helps create a protein found in fast-twitch muscle fibers. For this reason, a person with the dominance of this gene is more likely to excel in strength and hypertrophy-based sports.
Another gene is the MSTN gene, which produces the protein “myostatin,” also called the “Hercules gene.” It is a protein-based hormone that works at a physiological level to limit muscle mass. Likewise, there are other genes such as IGF1, MyoD, Pax3, etc.
For this reason, certain muscle building genes dominate in some people, helping them build muscle with much less effort. Still others may train hard but recover quite quickly because of these genes.
Scientists have discovered many muscle-building genes, but how they work is quite complicated and not yet fully understood. And it is likely that many more such genes will be discovered in the future.
– Hormones play a crucial role in every aspect of sport. For example, testosterone is the most anabolic hormone in the human body, primarily responsible for strength and hypertrophy gains.
However, according to studies, circulating testosterone levels are a hereditary trait. Using genetic association testing, researchers have identified 2,571 genetic variants that affect testosterone levels or related sex hormones. The same goes for other anabolic hormones like GH, IGF1, etc.
For this reason, some people have higher levels of circulating free testosterone and higher levels of GH and IGF1.
However, if we talk about percentage influence, studies have shown that skeletal muscle is a highly heritable quantitative trait, with inheritance estimates for muscle strength at 30-85% and for muscle mass at 50-80%. The rest depends on external factors, which include training, nutrition, hormonal profile, as well as extreme courage, persistence and endurance.
This simply means that regardless of whether you are genetically predisposed to a sport or not, you can perform at your best in it through the proper use of the external factors mentioned above.
In one study, scientists analyzed the results of 3,012 adults between the ages of 18 and 55 who had not previously participated in exercise to find out how our genes can influence three important types of physical activity.
Muscular strength, cardiovascular fitness and anaerobic power are key factors in a person's fitness, well-being and quality of life. All participants showed improvements after their training, but to varying degrees, even when they performed the exact same training.
By combining data from 24 different studies, researchers found that genetic differences accounted for 72% of the different results in people performing identical exercises to improve muscle strength. In total, the study identified 13 genes that are responsible for how well the body responds to cardiovascular fitness, muscle strength and anaerobic strength exercise.
Another study that analyzed why some weightlifters' muscles grow much faster than others has identified a set of 141 genes that appear to regulate the growth of the body's skeletal muscles.
I often hear teenagers use genetics as a classic excuse for failing to build muscle, gain strength, and lose fat. Undoubtedly, genetics play an important role in all of your physical goals, as we saw above, but you simply have no control over your genes.
The only factors you can control are your training, your diet, your sleep, and the tremendous amount of hard work and consistency that go into sculpting your desired physique. The world is full of examples of legendary athletes in all sports who overcame every possible genetic limitation because they didn't care if they had one.
Undoubtedly, some people react quickly and others react slowly, as we have seen in the research studies mentioned above. But let me ask you a question. What if you react slowly? What alternative do you have other than optimizing all aspects of your training, diet and recovery methods? The second alternative is only one – “Give up”, and that is your decision.
