Tennis is often celebrated as a heart-healthy workout—a high-stakes game of fast sprints, powerful serves, and quick directional changes. But how does an hour on the court actually impact your cardiovascular system during play, and what happens to your body once you step off the court? To find out, Oura’s data science team analyzed de-identified and aggregate data from adult members across 11 global markets over a one-month period (July 17 – Aug…