Living an active lifestyle is essential for your long-term health. How many times have you heard a statement like that? Often, I would assume, and for a good reason, it is true. But why? Have you ever wondered what is happening inside your cells while you’re out for a jog or lifting weights at the gym? Have you ever thought about how it could affect your genetics? Exercise can alter how your genes are expressed, so let’s dive into the influence of exercise on your epigenetics.
DNA Methylation and Muscle Tissue
One of the most notable changes to the epigenome (all the factors that regulate gene expression) in response to exercise is DNA hypomethylation, the removal of methyl groups from DNA. As discussed here, methylation of DNA is a mechanism of gene silencing; however, studies have found that following a resistance training session, the DNA of key genes in skeletal muscle is less methylated and thus allows for greater expression of these genes. It is this increase in gene expression of genes such as myocyte enhancer factor 2 (MEF2) and NADH:ubiquinone oxidoreductase subunit C2 (NDUFC2) that allows you to exercise at an increased intensity. Additionally, greater hypomethylation is observed following a second resistance training session as compared to the initial resistance training session, which suggests the potential of an “epigenetic memory” in response to exercise. In other words, the more you train, the easier your epigenome can adapt . However, it has also been found that elite athletes have certain gene variations in the enzymes involved in DNA methylation that have a greater impact on hypomethylation and thus this may lead to increased muscle mass .
Expression Changes in Fat Cells
Exercise does not only affect the methylation of muscle tissue but also fat tissue. Rönn et al., 2013, analysed methylation patterns of adipocytes (fat cells) in middle-aged men who lived a sedentary lifestyle and underwent a six-month endurance-training programme. They observed an increase in hypermethylation (an increase in methylation marks) across the genome and a subsequent reduction in gene expression. Notably, there 21 genes associated with type 2 diabetes and 18 genes associated with obesity were silenced .
Exercise and Histones
Epigenetics does not only relate to DNA chemical changes but also includes those chemical changes on histones. Histones are the proteins that DNA wraps around when forming chromosomes. When they are methylated, the genes are not expressed, and when they are acetylated, genes are able to be expressed. Just like with DNA, exercise can influence histone modifications and affect the accessibility of genes, leading to changes in gene expression. Exercise has been shown to induce modifications in histones associated with muscle-related genes, inflammation, and metabolic pathways. For example, exercise has been found to increase histone acetylation, a modification associated with gene activation, in skeletal muscle .
These are just some of the ways in which your epigenome can change in response to exercise, but there are so many more areas that scientists are still investigating. What is clear is that exercise can have profound changes on your body at a DNA level, which emphasises the importance of maintaining an active lifestyle. If you are looking to change your epigenome through exercise, let BioCertica’s DNA fitness kit help you on your journey.
Written by: Jamie Fernandez, B.Sc Hons. in Genetics, Content Specialist
 S. L. McGee and M. Hargreaves, “Epigenetics and Exercise,” Trends Endocrinol. Metab., vol. 30, no. 9, pp. 636–645, Sep. 2019.
 I. Terruzzi et al., “Genetic polymorphisms of the enzymes involved in DNA methylation and synthesis in elite athletes,” Physiol. Genomics, vol. 43, no. 16, pp. 965–973, Aug. 2011.
 T. Rönn et al., “A Six Months Exercise Intervention Influences the Genome-wide DNA Methylation Pattern in Human Adipose Tissue,” PLOS Genet., vol. 9, no. 6, p. e1003572, Jun. 2013.