Why Tennis Adds 9.7 Years: Sport and Lifespan Data

TL;DR

The widely cited tennis longevity study comes from an analysis of the Copenhagen City Heart Study (Schnohr et al., Mayo Clinic Proceedings, 2018). Among roughly 8,500 adults followed for about 25 years, the sport associated with the greatest gain in life expectancy was tennis, at 9.7 years versus sedentary participants, followed by badminton at 6.2 years, football (soccer) at 4.7, cycling at 3.7, swimming at 3.4, and jogging at 3.2. The standout feature of the top sports is that they are social: they involve regular interaction with other people. The researchers proposed that this social dimension may help explain the larger gains, alongside the physical demands. Crucially, this is an observational association, not proof that tennis causes extra years of life. This article unpacks the numbers, the social-interaction hypothesis, and the important caveats. Calculate your life expectancy free at death-clock.app.

Does tennis really add 9.7 years to your life?

The 9.7-year figure comes from an analysis of the Copenhagen City Heart Study, which found that participants who played tennis had a life expectancy on average 9.7 years longer than sedentary participants. This is a striking association, but it is an association from observational data, not evidence that taking up tennis will add nearly a decade to any individual's life.

The analysis, published in Mayo Clinic Proceedings (Schnohr et al., 2018), drew on the long-running Copenhagen City Heart Study, a prospective cohort of Danish adults followed over decades. Researchers compared self-reported participation in different leisure-time sports with subsequent mortality, adjusting for factors such as age, education, smoking, alcohol, and other physical activity.

For the wider context on how different forms of exercise relate to lifespan, see the pillar guide, Exercise for Longevity: The Complete Protocol.

Which sports were linked to the longest lifespan?

The analysis ranked sports by the estimated gain in life expectancy versus sedentary participants, and racket and team sports topped the list. The full set of estimated gains reported in the Copenhagen analysis was as follows.

The pattern is notable. Tennis and badminton, both racket sports played with a partner or opponent, and football, a team sport, were associated with the largest gains. Solo activities such as cycling, swimming, jogging, and gym work were associated with smaller, though still meaningful, gains. The contrast between roughly 9.7 years for tennis and 1.5 years for health club activity is the part of the study that has attracted the most attention.

Why might social sports be linked to bigger gains?

The researchers proposed that the social nature of the top-ranked sports may help explain their stronger association with longevity. Tennis, badminton, and football all involve regular, structured interaction with other people, and social connection is itself a well-documented predictor of better health and lower mortality.

This is the study's central hypothesis rather than a proven mechanism. There are several plausible reasons social sports might be associated with larger gains:

• Social connection and mortality. Independent research, including a large meta-analysis in PLoS Medicine (Holt-Lunstad et al., 2010), found that stronger social relationships are associated with a substantially lower risk of death. Sports that build regular social contact may carry some of that benefit.
• Adherence and enjoyment. Activities done with others tend to be more enjoyable and easier to sustain over years. A sport you keep playing for decades delivers more cumulative benefit than a solo routine you abandon.
• Accountability. Arranging to play with a partner or team creates a commitment that makes regular activity more likely.
• Psychological benefit. Social interaction is associated with reduced stress, depression, and loneliness, all of which independently affect health.

Our pillar article notes the same theme: social exercise is associated with additional mortality benefit beyond the physical activity alone. The Copenhagen sport analysis is one of the clearest illustrations of that idea.

How strong is the evidence: association or causation?

This is observational evidence, and the differences between sports almost certainly reflect more than the sports themselves. People who play tennis differ systematically from sedentary people and from joggers in ways that affect lifespan, so the headline numbers should be read as associations heavily shaped by who plays each sport.

In the Copenhagen City Heart Study, participants reported their leisure-time activities at baseline, and researchers tracked deaths over the following decades. The study adjusted for several confounders, but important sources of bias remain:

• Socioeconomic confounding. Tennis, in particular, is associated with higher income and education in many populations, and both are strong independent predictors of longevity. Some of the apparent tennis advantage may reflect the characteristics of people who play it rather than the sport.
• Reverse causation. Healthier people are more able to take up and continue demanding social sports, so the direction of the association can run from health to sport as well as the other way.
• Self-report. Activity was self-reported, which introduces measurement error.
• Residual confounding. Diet, baseline fitness, and other lifestyle factors cannot be fully accounted for.

The honest summary is that the Copenhagen analysis shows a robust association between social sports and longer life expectancy, that the social-interaction hypothesis is biologically and behaviourally plausible, but that no one should treat 9.7 years as the causal effect of tennis. The study is best understood as evidence that enjoyable, social, regular physical activity is linked to better outcomes, not as a prescription to switch sports for a guaranteed result.

What should you actually take from this study?

The practical lesson is not that tennis is uniquely life-extending, but that the best exercise for longevity is one that is regular, enjoyable, and ideally social, because those features drive long-term adherence and may add a social-connection benefit on top of the physical one. The sport you will keep doing matters more than the sport with the highest number in a single study.

Sensible takeaways:

• Choose activities you enjoy enough to sustain. Cumulative years of activity beat short bursts of an "optimal" sport you dislike.
• Build in social contact where you can. Joining a club, league, or regular group adds both accountability and the social dimension highlighted by the study.
• Do not abandon solo training. Cycling, swimming, and jogging were all associated with meaningful gains, and they remain excellent ways to build cardiorespiratory fitness, one of the strongest predictors of lifespan. See VO2 Max: The Strongest Predictor of Lifespan and Zone 2 Cardio Explained: Train for a Longer Life.
• Add resistance training regardless of sport. Racket and team sports do not replace strength work, which has its own mortality association, covered in Strength Training and Mortality: What the Data Says.

Reducing sedentary time also matters whatever sport you choose, as explored in Sitting and Mortality: How Much Sitting Is Too Much?.

Frequently asked questions

Did the study prove tennis causes a longer life?

No. The Copenhagen analysis is observational and shows an association, not causation. People who play tennis tend to differ from sedentary people in income, education, and baseline health, all of which affect lifespan. The 9.7-year figure should not be read as the causal effect of taking up tennis.

Why did tennis beat jogging and cycling in the study?

Tennis, badminton, and football were associated with larger gains than solo activities. The researchers proposed that the social interaction involved in these sports may contribute, alongside the physical demands and likely differences in the people who play them.

Does badminton count almost as much as tennis?

In the Copenhagen analysis, badminton was associated with a 6.2-year gain in life expectancy versus sedentary participants, second only to tennis at 9.7 years. Both are social racket sports, consistent with the study's social-interaction hypothesis.

Should I switch from running to tennis to live longer?

Not necessarily. The best activity is the one you will do consistently for years. Jogging was still associated with a 3.2-year gain, and cardiorespiratory fitness from running is a strong predictor of lifespan. Adding a social element to whatever you do is the more defensible takeaway.

Is the social benefit of sport supported by other research?

Yes. Independent studies, including a large meta-analysis in PLoS Medicine, link stronger social relationships to lower mortality. This supports the plausibility of the social-interaction hypothesis, though it does not prove it explains the sport rankings.

About the author

Yanni Papoutsis is the founder of Death Clock and writes evidence-based guides on longevity, drawing on peer-reviewed research in exercise science, epidemiology, and preventive medicine.

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Want to see how your sport and activity habits relate to your projected lifespan? Use the Death Clock life expectancy calculator to explore the factors that shape it. Calculate your life expectancy free at death-clock.app.

Sources

• Schnohr P, et al. Various Leisure-Time Physical Activities Associated With Widely Divergent Life Expectancies: The Copenhagen City Heart Study. Mayo Clinic Proceedings, 2018. PubMed search
• Schnohr P, et al. Physical activity in leisure time and risk of death. Copenhagen City Heart Study. PubMed
• Holt-Lunstad J, et al. Social Relationships and Mortality Risk: A Meta-analytic Review. PLoS Medicine, 2010. PubMed search