EXERCISE AND THE IMMUNE SYSTEM BOOST Scientists have been chasing the link between exercise and inflammation for generations. Picture this: it all started back in the early 1900s, when someone noticed Boston Marathon runners had a surge of white blood cells after crossing the finish line. Something was clearly happening deep inside the body, but nobody really knew what. Fast-forward to today, and Harvard Medical School is turning the lights on. Their new study, published in Science Immunology, reveals that the magic of exercise goes way beyond stronger muscles or a healthier heart—it’s actually about how movement rewires your immune system. In their experiments with mice, the Harvard team discovered that when muscles get inflamed after exercise, they call in a special squad of immune cells called Tregs (short for regulatory T cells). These Tregs aren’t just peacekeepers—they help muscles burn energy more efficiently and boost endurance. Tregs have always had a reputation for keep...