Why is Exercise Good for You? Scientists are Finding Answers in our Cells
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Photo by Zakaria Boumliha: https://www.pexels.com/photo/man-running-on-sand-field-2827392/
Decades of evidence shows that exercise leads to healthier, longer lives. Researchers are just starting to work out what it does to cells to reap this reward.
When Bente Klarlund Pedersen wakes up in the morning, the first thing she does is pull on her trainers and go for a 5-kilometre run — and it’s not just about staying fit. “It’s when I think and solve problems without knowing it,” says Klarlund Pedersen, who specializes in internal medicine and infectious diseases at the University of Copenhagen. “It’s very important for my well-being.”
Whether it’s running or lifting weights, it’s no secret that exercise is good for your health. Research has found that briskly walking for 450 minutes each week is associated with living around 4.5 years longer than doing no leisure-time exercise1, and that engaging in regular physical activity can fortify the immune system and stave off chronic diseases, such as cancer, cardiovascular disease and type 2 diabetes. But, says Dafna Bar-Sagi, a cell biologist at New York University, the burning question is how does exercise deliver its health-boosting effects?
“We know that it is good, but there is still a huge gap in understanding what it is doing to cells,” says Bar-Sagi, who walks on a treadmill for 30 minutes, five days a week.
In the past decade, researchers have started to build a picture of the vast maze of cellular and molecular processes that are triggered throughout the body during — and even after — a workout. Some of these processes dial down inflammation, whereas others ramp up cellular repair and maintenance. Exercise also prompts cells to release signaling molecules that carry a frenzy of messages between organs and tissues: from muscle cells to the immune and cardiovascular systems, or from the liver to the brain.
