A low-cost test using nothing more than a tennis ball might help predict your lifespan, according to health researchers in the UK and Canada. Experts say that grip strength—how firmly you can squeeze something—offers key clues about overall health, future risk of disease, and even how well your body is aging.
This simple test can be done at home without special tools. All you need is a soft ball and a timer.
How a Tennis Ball Can Help Predict Longevity
Joshua Davidson, a researcher at the University of Derby, says grip strength is one of the best ways to check your physical health. “Just sit in a chair and squeeze a tennis ball for as long as you can,” he explains. “Aim for 15 to 30 seconds. If your hand starts to shake or get tired before that, it may be a sign to work on strength.”
Grip strength has long been used in medical studies, often with a device called a hand dynamometer. It measures the pressure your hand and forearm can apply. These devices are now available for home use, many of them connected to smartphone apps. But Davidson believes a tennis or stress ball still does the job for regular check-ins.
What Weak Grip Strength May Mean for Your Health
Mark Peterson, a health professor from the University of Michigan, says weak grip strength can signal more than just trouble opening jars. “It reflects total muscle health,” he says. “It shows if you’re active or spending too much time sitting still.”
Weak grip strength has been linked to higher risk of falling, poor recovery from illness, and even early death. One large study involving over 140,000 people found that low grip strength was a better predictor of early death than high blood pressure.
A separate long-term study followed people from the 1960s for more than 40 years. Those who lived to be 100 were far more likely to have had strong grip strength in their youth.
Muscle Strength Affects More Than Movement
Professor Darryl Leong from McMaster University says grip strength reveals more than just how strong you are. “It reflects your diet, activity level, and general health,” he notes. That’s why doctors are starting to use it to spot early signs of trouble.
For instance, low grip strength is linked to sarcopenia—a condition where muscles shrink with age. This can lead to falls and slow healing from injury.
Guillaume Paré, also from McMaster, says even a weak handshake can reveal problems. “Thin fingers and low muscle tone usually mean there’s muscle loss,” he explains.
But there’s more. Muscle tissue helps balance blood sugar. So weak grip strength can also signal a risk for type 2 diabetes, brittle bones, low energy, and even depression or memory loss.
Your Genes May Age Faster With Weak Muscles
In 2022, researchers looked at the DNA of 1,275 people and found that weak grip strength was linked to faster biological aging. Changes in DNA methylation—the chemical tags that switch genes on or off—were more common in people with low grip scores.
Peterson says this could explain why people with weak muscles often recover poorly from lung infections or other illnesses. “Strong muscles help your lungs clear mucus,” he explains. “If you can’t do that well, the risk of pneumonia and death goes up.”
Grip Strength Also Matters in Youth
Strong hands aren’t just important for older adults. A study in Brazil found that teens who spent more time on screens had weaker grips. This could affect their long-term health. “Poor grip strength in youth is linked to future health problems,” says Paré.
Even Olympic success may be linked to grip power. Countries with stronger average grip strength tend to earn more medals, some researchers say.
Easy Ways to Boost Grip Strength at Home
The good news? Anyone can improve grip strength. Davidson suggests doing the tennis ball test regularly. “Over time, your muscles get stronger,” he says. “You’ll notice you can squeeze longer and harder.”
You can also use wrist curls, bicep curls with a weight, or household items like water bottles. Two to three sets of 10 to 20 reps can help.
Leong adds that overall fitness helps, too. Leg strength and movement are also important. He recommends the “get-up-and-go” test: Stand up from a chair, walk three metres, turn around, and sit back down. Time the full movement. It shows how strong and mobile you are.
Why Grip Strength Shouldn’t Be Ignored
“Muscle strength is about more than how much you can lift,” Davidson says. “It’s about how well your body works and how long it stays healthy.”
Experts agree that regular movement, balanced meals, and light strength training can protect your health at any age. And one of the best places to start? Pick up a tennis ball.