Although a person's genetic code remains unchanged from birth, the DNA molecules that make it up undergo chemical changes throughout life. And as Juleen Zierath of the Karolinska Institute has shown, one of the main drivers of these changes – called epigenetic changes – is the practice of physical exercise. In fact, these DNA modifications could explain why playing sports is so beneficial for the body. "Our muscles are really plastic," explains Zierath, an expert in Molecular Medicine.
Specifically, their experiments show that skeletal muscle DNA taken from a person after intense exercise contains fewer methyl groups attached to its molecules than before exercise. These changes occur in stretches of DNA that are normally used by enzymes called transcription factors, which Ziertah likens to "keys" that "unlock genes in muscles." And those keys work best when there are no methyl groups "in between" to "get in the way." Therefore, the DNA changes caused by exercise increase the muscle's ability to work.
As if that were not enough, exercise increases and improves the metabolism of sugars and fats. " Exercise is medicine, and it alters our epigenome, improving health , from a short career," concludes the researcher in the journal Cell Metabolism .
