Most people (hopefully) know that exercise and physical activity are beneficial to almost everyones physical and mental health. Exercising improves one’s mood, boosts energy, controls weight, helps the body fight against diseases, reduces stress, and many more life benefits. A new study by a group of scientists in Sweden discovered how the influence of physical exercise actually has that beneficial effect on the human body.
The scientists focused their work on 23 young, healthy men and women at the Karolinska Institute in Stockholm. The participants were asked to exercise on stationary bikes for 45 minutes, four times per week, for three months. The scientists understood that it would be difficult to study the full changes on each person because they can’t isolate the other aspects of someone’s life like diet or other behaviors. Because of this issue, each person only exercised one leg so they essentially became their own control group.
After the three months had passed, the scientists clearly saw that the exercised leg was stronger. They also studied the DNA of the muscle cells and compared them between each leg. The genome of muscle cells on the exercised leg had new methylation patterns. DNA Methylation is the process of methyl groups attaching to the outside of a gene and making the gene more or less able to respond to biochemical signals. This entire study is also known as epigenetis. Epigenetics is the study of modifications of DNA influenced by the environment. The scientists found that exercise has a huge effect on human epigenetics based on methylation patterns.
The experiment showed that many of the methylation changes were on the enhancer part of the genome. Enhancers “bind to activator proteins which help connect transcription factors to RNA polymerase and the promotor region to turn on transcription of a gene” (from Mrs. Newitt notes packet). The enhancers amplified the expression of proteins by genes that effect energy, insulin, muscle inflammation and muscle pain.
Exercising is good for you and now we know why. It affects how healthy and fit our muscles become. The results of this study will now help lead other scientists into methylation pattern and gene expression research.
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