Perhaps Juleen Zierath, a professor of clinical integrative physiology, says it best—that we’re not only what we eat. We’re also “what we do,” namely exercise. Zierath and her colleagues discovered that healthy, but inactive, young adults had immediate changes to their muscle cells’ genetic material after engaging in only a few moments of exercise on a stationary bicycle.
Just to make sure at the outset that there’s no mistake. . . the researchers did not find that exercise changes a person’s genetic code. We get our genetic code from our parents, but lifestyle and environmental factors play roles in how those genes are expressed. What the researchers did find, however, is that exercise directly and positively affects DNA methylation, the process by which genes are told whether or not to remain “on” or “off.” In fact, the scientists found that exercise affects our DNA in a way that improves normal bodily function.
That being said, this recent study was published in the peer-reviewed journal Cell Metabolism and highlighted the fact that just a few minutes of rigorous exercise catalyzed almost immediate changes in DNA that improve the ways in which health-regulating genes express themselves. Specifically, Zierath and her colleagues noted that exercise positively affects DNA to better transport fats, sugars and other nutrients throughout the body and also protects cells from oxidative damage.
Another one of the researchers in the study, Dr. Donal O’Gorman, director of the Center for Preventive Medicine at Dublin City University, makes this observation: “The changes in methylation and expression for the genes studied are important for mitochondrial function, glucose transport as well as fat transport and oxidation. The findings support the view that regular activity is necessary for metabolic health and the prevention of chronic diseases such as type 2 diabetes.”
Although the DNA changes were temporary, they are still notable. They reinforce just how the body responds to exercise as well as how muscles that are exercised react favorably as far as nutrient transport and growth. Just a few minutes of vigorous exercise daily can directly impact your DNA—essentially instructing it on how to distribute nutrients, to build muscles and to improve overall health. Zierath adds, “Our muscles are really plastic. We often say, ‘You are what you eat,” well, muscle adapts to what you do. If you don’t use it, you lose it, and this is one of the mechanisms that allows that to happen.”
The researchers explain that their study is evidence of how environmental influence, such as exercise, causes muscles to adapt. Furthermore, the genetic changes that resulted from exercise occurred in the epigenome, which is responsible for the expression of genes. Through the epigenome, environmental factors such as diet—even prenatal nutrition—stress, exercise and other lifestyle factors can imprint genes in the present and for future generations.
The takeaway? Our inherited genetic code is not the final word. Epigenetic factors, including diet and lifestyle, can radically change what our genes do.