Nature vs. nurture: Can exercise change your genes?

We have all heard the phrases, “It’s your genetics” or “it runs in the family”, but how true is this? Can you defy your genes? Are we destined to have small calf muscles if our parents have small calf muscles? Why can some people lift or press a lot of weight the first time that they try the move? How can that be if not due to genetics?

The fact is that people and their bodies respond to strength training at different levels. In a study by published in Frontiers in Physiology, it was determined that not all individuals respond to an exercise program in the same manner. It was found that genes are a factor in the body’s response to exercise.

The data suggests different genetics significantly affect both tolerance for exercise, ability and someone’s want and drive to complete an exercise program. Genetics can affect how muscles adapt and respond to training. The data also showed that speaking to individuals about the benefits of health and exercise prior to the testing may increase the chances of sticking to a program or exercise plan.

But can we change our genes through exercise? Scientists already know that exercise can activate certain genes while cooling others down. However, a different study found that exercise can actually change the genes themselves, altering their shape and function.

This is called epigenetics, a process where the functions of genes are changed, but not the actual DNA. The scientists took muscle samples from 23 participants and had them exercise one of their legs on a bike for three months. At the end of the three-month trial, not only were the exercised legs of the participants strong and more powerful, but the genes within the muscle cells had changed. Those genes within the non-exercised leg did not show the same genetic changes.

The genes that determine how healthy and fit we are: energy metabolism, insulin response and inflammation within muscles were the ones altered through an exercise program. While it is not known if the changes in the genes remain after exercise, it is clear that we can effect change to our genes to make them healthier and more functional simply through endurance training.

To answer the question, “is your body a slave to genetics?”, the answer is yes, but to a degree. Because exercise and diet can change some of our genes at least temporarily to make our bodies more efficient, there are still some things that you can do to affect your health and weight despite your genes and predispositions!