Exercise Prompts Changes Down to Your DNA

New research on twins finds that fitness can significantly lower metabolic risk, even when it runs in the family.


  • A study published in Scientific Reports, involving 70 pairs of twins, found that while exercise can’t change your DNA or genetic risk for disease, it can alter how your body reads a DNA sequence, helping to lower your risk for chronic conditions like metabolic disease — even if it runs in the family.
  • The researchers looked at both moderate- and vigorous-intensity physical activity and while both improved cellular function, vigorous exercise did so more significantly.

Because exercise can have profoundly different effects from one individual to another, it’s tricky to generalise benefits — unless you’ve recruited identical twins for your study, that is.

New research in the journal Scientific Reports looked at how exercise affected 70 pairs of identical twins over a seven-year period. Because these twins had the same genetics and environmental factors growing up, it was easier to determine how exercise played a role in health risks, all the way down to a molecular level. That’s especially true because many of the twin pairs had different amounts of regular physical activity compared to one another.

Those in the twin pairs who were more active had lower signs of metabolic diseases, such as excess body fat around the waist, high cholesterol, high blood sugar, and elevated blood pressure. This means they have a lower risk of metabolic syndrome, a condition that can lead to stroke, type 2 diabetes, and heart disease.

Part of the reason why exercise improves metabolic health has to do with how physical activity creates epigenetic changes, according to the study’s lead author, Dr Michael Skinner, a biologist at Washington State University. He told Runner’s World that epigenetics is defined as molecular factors around DNA that regulate how genes are switched off and on. Basically, epigenetics determines how your body reads a DNA sequence.

Unlike DNA itself, which is unchangeable, epigenetic factors can be significantly changed by lifestyle behaviours. For example, previous research in Epigenomics found epigenetic patterns can shift due to diet, tobacco use, environmental pollutants, working on night shifts, and psychological stress. That research also mentions exercise, but the recent study has been able to dive deeper into how extensive the changes can be thanks to more physical activity.

“Since twins were used, this removed the genetic variable,” said Skinner. “We could see that environmental impacts, like physical activity, act on the individual to change cellular function through epigenetics. So, when a person exercises, they change their epigenetics and that changes their gene expression.”

The result is improved cellular function, he added. For example, the body may change where fat is stored, or how blood pressure is regulated. Skinner said the research found both moderate and vigorous physical activity impacted epigenetics but vigorous activity had a more dramatic and significant effect.

The takeaway? Even if you have metabolic disease running in your family, you can lower your risk of developing a condition like heart disease or type 2 diabetes by focusing on lifestyle behaviours that boost your epigenetic power. Regularly opting for vigorous activity specifically won’t change your genes — but it can have a significant effect on how those genes operate.

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