Nearly 1 in 8 Americans have turned to GLP-1s to shed pounds. For many, these drugs offer a powerful starting point to trimming their waistlines — but not a complete path to long-term health.

Lasting health isn’t defined by the scale. Sustainable improvements come from building healthier lifestyles over time — especially regular physical activity — which no pill or injection can replace.

And not all exercise is equally effective. While any movement is better than none, when researchers have looked closely at which activities deliver the greatest health benefits over decades, the differences are striking.

One sport consistently rises to the top: tennis.

People who play tennis gain 9.7 years in life expectancy, on average, compared with sedentary individuals — an effect so large it rivals some of the most consequential public-health gaps we know, including the gap between smokers and non-smokers. In the same study, no other exercise came close. Cycling, swimming and jogging were associated with about three additional years of life expectancy.

What makes tennis remarkable isn’t that it promotes good health. It’s how it does. Tennis delivers an unusually high return on time and effort. An hour of tennis can burn 500-800 calories. But unlike a treadmill or a stationary bike, tennis rarely feels monotonous. There’s no screen to stare at and no reps to count. The focus is outward — to beating your friend or hitting that perfect serve.

Tennis also delivers something many workouts don’t: integrated, whole-body fitness. Players sprint, stop, rotate and recover in rapid succession, developing strength, coordination and agility.

The cardiovascular benefits are equally distinctive. Tennis is built around short bursts of high-intensity effort followed by brief recovery periods — an interval pattern that’s especially good for heart health. Research shows that just three hours of tennis per week is associated with a 56 percent reduction in cardiovascular disease mortality and a 47 percent reduction in all-cause mortality.

Tennis is also effective at improving strength and bone density. Because it’s a weight-bearing sport involving quick pivots, tennis helps promote bone density in the spine, arms and legs while strengthening the upper body and grip.

Just as telling as the health benefits is a simpler fact: people actually stick with tennis. The sport is social by nature.

It’s easy to picture how it happens. A standing doubles game that survives busy seasons. Coworkers who meet weekly after leaving the office. Parents who hit while their kids take lessons on the court. These routines are genuinely fun. This combination of not just physical, but also mental health, may play a role in why tennis may have such a positive effect on life expectancy.

Accessibility plays a role too: there are roughly 270,000 tennis courts across the U.S., most of them free and open to the public.

Tennis has a way of pulling you in. Once you hit a flawless backhand or serve your first ace, the satisfaction is immediate — and so is the desire to come back. Not because it feels like exercise, but precisely because it doesn’t.

Millions of Americans will use fad diets and weight loss drugs this year to kickstart their health journeys. But if they want to truly get healthier, they’ll consider picking up a racquet.

– Angus Mugford, PhD, is the managing director of Athlete Performance and Operations at the United States Tennis Association.