Social Sweat: The Real Lifespan Boost?

A 25-year study tracking 8,577 adults found that tennis players outlived sedentary people by nearly a decade — and the reason why may have nothing to do with the sport itself.

Story Snapshot

The Copenhagen City Heart Study found tennis players gained 9.7 years of life expectancy compared to sedentary people.
Sports with built-in social interaction — tennis, badminton, soccer — showed the biggest longevity gains. Solo gym workouts added only 1.5 years.
Tennis mimics high-intensity interval training, delivering short bursts of intense effort followed by rest — one of the most efficient workout formats known.
Researchers openly admit the study is observational, meaning tennis may not be the cause — wealthier, more socially connected people tend to play tennis, and those factors alone extend life.

The Study That Started the Conversation

In 2018, researchers published findings from the Copenhagen City Heart Study in Mayo Clinic Proceedings. They followed 8,577 adults for 25 years, from the early 1990s through 2017. The goal was simple: figure out which leisure sports were linked to longer lives. The answer surprised a lot of people. Tennis players showed a 9.7-year gain in life expectancy compared to people who did nothing at all. That number spread fast — and for good reason. It is a striking figure.

The study did not stop at tennis. It ranked a range of activities by their associated longevity gains. Badminton came in second, soccer third. At the bottom of the list sat health club activities — solo gym workouts — with a gain of just 1.5 years. That gap between social sports and solo exercise is the most telling detail in the entire study, and it points toward something bigger than a racket and a ball.

Why Social Sports Beat Solo Workouts by a Mile

The researchers pointed directly at social interaction as a key factor. Tennis is not just exercise. Every match involves another person. You schedule it, you show up for someone, you talk before and after. Over years, those interactions build real relationships. The Harvard Study of Adult Development, one of the longest-running studies on human happiness, found that the quality of a person’s relationships is the single strongest predictor of how long they live. Tennis delivers that relationship-building almost automatically.

Dr. Ed Laskowski, co-director of Mayo Clinic Sports Medicine, added another layer. He noted that tennis naturally mimics high-intensity interval training — roughly 30 seconds of hard sprinting followed by a recovery period, repeated throughout a match. That pattern is one of the most efficient ways to train the heart and body. You get a serious cardiovascular workout without ever thinking of it as a workout. That combination of social connection and physical intensity is rare in a single activity.

The Honest Catch Buried in the Data

The researchers themselves flagged the biggest problem with their findings. Because the study is observational, it cannot prove that tennis caused people to live longer. It only shows that tennis players tended to live longer. That distinction matters enormously. Tennis has historically been a sport of the affluent. People with more money eat better, see doctors more often, live in safer neighborhoods, and face less chronic stress. All of those factors independently add years to a life.

Researchers adjusted their models for known confounding variables, but they acknowledged that selection bias remains a real concern. A doctor commenting on the study put it plainly: tennis players tend to be wealthier and more socially connected, and those traits alone predict longer lives. That does not mean tennis is useless — it almost certainly is not. But the honest read of the data is that tennis is associated with longer life, not proven to cause it. Anyone selling you certainty on this is outrunning the evidence.

What the 9.7-Year Figure Actually Means

Context matters here. The 9.7-year gain compares regular tennis players to people who are completely sedentary. That is an extreme comparison. Most people are not entirely sedentary. The gain over someone who walks regularly or swims occasionally would be much smaller. Longevity science is full of this pattern — dramatic numbers that shrink when you look at who is actually being compared. A UK Biobank study found that people shifting from the very worst diets to the healthiest ones could gain up to 10 years of life expectancy, but average adults making moderate improvements gained closer to 3 years. The tennis number likely follows similar logic.

None of this means you should skip the court. The evidence that social, interval-based exercise is good for your heart and brain is solid across many studies. A separate British analysis of more than 80,000 adults found racket sport players had a 47% lower risk of dying from any cause and a 56% lower risk of dying from cardiovascular disease. That is a different study with a different population, and it points in the same direction. The pattern is consistent enough to take seriously, even without a definitive causal proof. Pick up a racket. Find a partner. The science, imperfect as it is, keeps pointing the same way.