It is known that various signals that come from the external environment (from environmental or lifestyle factors) can “turn on” some genes and “turn off” others. This is done by redistributing the so—called methyl groups, molecules that attach to DNA by special enzymes and affect whether the gene is activated or deactivated. Such changes in gene expression are called epigenetic. These signals do not change the DNA sequence itself, all the genetic letters (nitrogen bases) remain in place — which is why they say that the epigenetic mechanism works “above the genes”, and not inside them. Changes in gene activity that occur under the influence of external signals can affect a person’s health and life, as well as be inherited. For example, the quality of inhaled air, lifestyle, bad habits, diet or sports can change the epigenetic “landscape”. We will talk about the latter.

A team of researchers from the Karolinska Institute in Sweden decided to find out what epigenetic marks physical exercise can leave on human DNA. To do this, the authors selected a group of men and women who had to exercise on an exercise bike for three months, but with one condition — they were told to train only one leg. Why was it necessary? The fact is that the epigenetic mechanism is very sensitive to various signals sent from the outside, so it is always quite difficult to determine that the changes occurred as a result of training, and not for any other reason. But this can be easily verified if you compare one leg with the other: the past epigenetic modifications in both legs are the same, and it will not be difficult to discover new ones after exercising on only one of them. Before and after the three-month sessions, participants underwent a biopsy of their leg muscles. Of course, by the end of the study, one leg had clearly become stronger than the other. However, the analysis also showed that the activity of a number of genes changed in the trained leg, most of which regulated cell energy, inflammatory processes and the cellular response to insulin. In an untrained leg, nothing like this happened. Thus, it is safe to say that sports activities affect DNA, which means that changes can also occur in our physiology and well-being.

Even short-term exercise can have an epigenetic “effect,” researchers from Sweden’s Lund University have found. They conducted an experiment with young men who had a slight excess of their body mass index, but were generally healthy. According to the conditions, the volunteers had to do aerobics or cycling three times a week for six months. However, men often skipped workouts (on average, they went there 1.8 times a week). Nevertheless, after conducting a genetic analysis, the scientists saw that even with such minor physical activity, the participants had positive changes in 7,000 genes. Moreover, modifications occurred in the expression of those genes that were associated with type 2 diabetes and obesity.

Scientists from Belgium, the Netherlands, and the United Kingdom have found that people who practice yoga, meditation, Qigong, and tai chi have altered stress-related genes. They conducted a meta-analysis of 18 studies covering data from about 900 people who engaged in one of the listed practices. Analysis of gene expression has shown that regular exercise leads to a decrease in the activity of the transcription factor NF-kB, which plays a key role in the development of inflammation associated with the body’s response to stress. When a person experiences stress, the sympathetic nervous system is activated in his body and there is an increase in the production of NF-kB molecules, which regulate the expression of genes involved in the synthesis of inflammatory cytokine proteins. Prolonged stress produces a lot of cytokines, and this causes many problems: for example, it leads to the development of diseases and accelerates aging. A review of studies showed that 81% of people who practiced yoga, meditation, Qigong, or Tai chi had reduced levels of NF-kV. Because of this, the expression of genes responsible for cytokine production decreased, which means that inflammation in the body decreased. This was the reason for the beneficial effect of such practices.

Sports can help even those who have a genetic predisposition to obesity. An international team of experts conducted a meta—analysis of 60 studies covering data from more than 200,000 people and found that regular physical activity reduces the activity of at least 11 genes associated with overweight, including the FTO gene, which increases the likelihood of obesity by almost 30%.

Experts from Massachusetts General Hospital have proven that increasing physical activity can reduce the risk of depression among people who are predisposed to this disorder. For each of the 8,000 study participants, they calculated the genetic risk, and then conducted a survey among them about how long it takes them to exercise and what kinds of sports they do. The subjects’ health status was then monitored for two years. It was found that people who were the most active had a lower tendency to develop depression, although they had a high genetic risk. They were 17% less likely to experience a new case of depression. According to scientists, four hours a week will be enough to protect against repeated cases of depression. It doesn’t matter what type of physical activity you engage in: both high-intensity exercises (aerobics, fitness equipment, dancing) and moderate exercise (yoga or Pilates) will be useful.

A sedentary lifestyle can reduce the activity of genes that are responsible for the normal functioning of mitochondria— the “energy stations” of cells. Scientists from the University of Milan have found that lack of exercise reduces the activity of one of these important CDK5Rap1 genes, which leads to impaired mitochondrial function. And this, in turn, is fraught with the development of insufficient energy supply to cells, metabolic disorders, and further cellular damage, including cell death.

All such experiments show that even if you get “wonderful” genes from your parents, they can easily be ruined by an improper sedentary lifestyle. Conversely, the “bad” genes found in the genus can be turned off with the help of sports. Persistent regular training (especially in combination with proper nutrition and the rejection of bad habits) is the key to “correcting” the malfunction of genes, which means a long life and youthfulness of the body.