In one major study, tennis was linked to the longest life. Consistency is the hard part.

The Copenhagen City Heart Study followed 8,577 adults for up to 25 years and compared life expectancy across different leisure-time sports with that of sedentary participants. Tennis was associated with the largest gain in the study: about 9.7 additional years of life on average.

The biggest gains came from sports that are usually social: tennis (9.7), badminton (6.2), and soccer (4.7). More solitary activities trailed behind: cycling (3.7), swimming (3.4), jogging (3.2), and gym-based exercise (1.5).

The researchers themselves pointed to a possible explanation. The activities with the largest life expectancy gains also tended to involve more social interaction, which they said warranted further investigation.

There are obvious caveats. Tennis players may differ from non-players in income, education, baseline health, and access to facilities. These studies do not prove that tennis itself adds years to life. But they do suggest something important: social sports may be easier to sustain, and sustained activity is where the benefit lives.

A separate study of more than 80,000 adults found that racquet-sport players had about 47% lower risk of death from any cause and 56% lower risk of death from cardiovascular disease than non-participants.

Again, that is association, not proof of causation. But two large datasets pointing in the same direction make the pattern hard to ignore.

Many sports likely improve cardiovascular health. Tennis may add something else: another person on the other side of the net. That means social support, a reason to show up, less time spent isolated, and a routine that can survive for years instead of weeks.

A weekly match is not just exercise. It is a recurring commitment between people. That could be part of why it lasts.