Can Exercise Really Change Your DNA?

Think exercise only builds strength and muscle mass? Think again! New research suggests even short workouts can modify gene expression too.

You rarely miss a workout (unless it’s a rest day). You’re unafraid to break a sweat and push your body to its limits. And why do you do it? The health benefits, of course! Not to mention it builds muscle definition, bone density, and improves metabolic health. But could there be another “sneaky” way it impacts your health? Could it affect your DNA, the genetic material that codes for everything from your appearance to your susceptibility to illness? Let’s look closer.

The Power of Epigenetics

While it may sound like science fiction or even something from the twilight zone, research suggests that working up a sweat through exercise may alter your genes, the long strands of DNA inside each of your cells. It doesn’t alter the genetic code itself. Instead, it changes how your genes express themselves or whether they express themselves at all.

Think of your DNA as a complex musical score, and epigenetics as the conductor that decides which parts will be loud or soft, fast, or slow, or even skipped entirely. Just as a conductor can interpret the same score in diverse ways, epigenetic modifications can lead to quite different outcomes from the same underlying DNA.

Epigenetics is a rapidly growing field. The best way to think of it is the study of how factors other than changes in the DNA sequence affect gene function and expression. Factors like lifestyle, environmental exposures, and even trauma can cause epigenetic changes that affect health and well-being, in positive or negative ways.

Exercise Leaves Marks on Your Genes

So how do we know that exercise affects how genes are expressed? In a groundbreaking study conducted by researchers at Karolinska Institute in Sweden, scientists discovered that only a few minutes of intense bicycling triggered epigenetic changes in the muscle cells of healthy volunteers.

The experiment was set up in an ingenious way. The subjects cycled vigorously on a stationary bike — but here’s the kicker. They only cycled with one leg while the other leg remained idle. This clever design meant that each participant served as their own control. This means any differences between the two legs were due to the exercise intervention.

After the intense cycling, scientists and healthcare professionals performed muscle biopsies on the legs of the participants. The results were mind-blowing! The legs that cycled intensely had modifications called methylations at thousands of sites along the muscle cell DNA. Methylations are tags that modify the expression of genes (epigenetically), either turning a gene off or on. Methylation is one type of epigenetic regulation of genes, changes that alter the expression of genes without changing the gene (or DNA) sequence. Exercise brought about these changes.

The researchers found that exercise-methylated genes are involved in insulin sensitivity, glucose and fat metabolism, and inflammation. In the exercised legs, activity altered these genes in a way that improved how they function. For example, insulin sensitivity improved, and inflammation declined.

Another type of epigenetic modification involves modifying chemical tags on DNA or the proteins that package DNA called histones. By modifying these tags, it changes gene expression. Methylation and histone modification are the two most common types of epigenetic mechanisms that affect how genes are expressed.

Also, be aware that unhealthy lifestyle habits, like smoking, drinking lots of alcohol, or eating an ultra-processed food diet, can have the opposite effect. It can modify gene expression in ways that worsen insulin resistance and inflammation.

Flexing Your Epigenome

The implications of this study for athletes and fitness buffs are profound and exciting. They suggest that even a brief bout of exercise can change gene expression through epigenetic mechanisms. Plus, exercise does it in a way that helps genes that affect health function better. Now take it one step further. Imagine the cumulative impact of a lifetime of gene modification from physical activity!

Regular exercise may subtly shape our gene expression in ways that boost health and cellular function. This could help explain why working out lowers the risk for so many health issues, from diabetes and heart disease to cancer and dementia.

Yet there are still questions. How long do these epigenetic changes last? What’s the optimal dose and what type of exercise is best? Can we target specific genes for maximal benefit? Researchers are asking these questions and looking for answers.

The Take-Away

Epigenetics is a young science, so there’s still much to learn. Yet one message rings loud and clear: what you do with your body today could resonate in your cells for years to come. Amazingly, there’s even evidence that epigenetic changes can pass down to future generations. It’s another reason to lead a healthy lifestyle during pregnancy. So, the next time you lace up your sneakers and head out the door, remember — you’re not just shaping your muscles, you’re shaping your DNA. And that may be the most profound workout of all.

What we know about epigenetics also illustrates how lifestyle can overcome some of the genetic cards we’re dealt with from birth. This is particularly true for health issues that are modifiable through lifestyle, like type 2 diabetes and cardiovascular disease. The message is empowering: the actions you take today and the choices you make matter. It also means you have more control over your health destiny than you think. So, what are you waiting for? Your genes are ready for their next workout!