How good is your grip? It’s not just a convincing handshake – or your ability to twist the lid off the jam – that’s at stake, if yours is feeble. “Good grip is integral to so many sports,” says Gareth Cole, head of performance at Coach London. “Whenever you need to hold on to an object, apply force to an object, pull yourself towards something or pull something towards yourself, you are recruiting the muscles in the forearm and hand that facilitate grip. Poor grip can also be the weakest link when you are lifting heavy weights.”

Outside of the gym, hand strength has been shown to have a strong relationship with our general wellbeing. Weak grip has been linked to poor cognitive function, osteoporosis, obesity, fall risk, rheumatoid arthritis and diabetes. A 2015 study, monitoring nearly 140,000 older adults over four years, found that a frail grip was related to higher incidences of heart attack, stroke, cardiovascular disease and even death. In fact, it predicted the risk of an early death more effectively than blood pressure, another important indicator of health.

“Handgrip strength acts as a biomarker for general health because of its relationship with so many other health-related variables, including bone-mineral density, nutrition status, cognitive impairment, sleep problems and quality of life,” says Richard Bohannon, a physical therapist who has researched grip strength. “It’s been referred to as a vitality meter.”

Of course, a limp fish of a grip doesn’t directly lead to a dodgy ticker or cognitive decline. But weak grip hints at poor musculoskeletal function throughout the body, which is a sign that the person is likely to be sedentary and does not do enough physical activity – the fourth greatest risk factor for mortality, according to the World Health Organization.

“The relationship between weak handgrip strength and poor cognition or cardiovascular health is likely to be due to the former indicating a low level of physical activity, which impacts on the latter,” says Professor Andre Rodacki, from the department of physical education, Federal University of Paraná, Brazil.

Like most aspects of physical capacity, grip strength declines as we get older. But even younger people should not be complacent. A 2021 study found that six out of 10 Brazilian adolescents had poor handgrip strength – and more screen time was associated with lower grip scores among teens. If your grip strength is already lacking in your youth, says Bohannon, you’re more likely to run into problems later in life.

So, does your inability to hold on to the dog’s lead when he spots a squirrel spell doom? “It might serve as the canary in the coal mine, prompting you to test other aspects of your physical capacity,” says Cole. “But you would need a battery of tests throughout the body to give a true picture.”

Rodacki agrees. “Hand-grip strength is too limited to a small number of muscles to represent a general physical state,” he says. “It is particularly problematic with older adults because force production by the muscles of the upper and lower body is affected differently by the ageing process. The reduction in muscle strength is significantly greater for the lower limb muscles.”

Grip strength is assessed using a dynamometer – a device you hold in your palm and squeeze as hard as you can with your fingers. (You can buy one for around £30, although the models used in medical settings are pricier and more accurate.) As you squeeze, the dial displays the amount of force you are exerting (measured in kilograms), just like when you step on to a set of scales. Your grip strength is recorded as the highest force reached in a single squeeze.

What’s considered normal? There are different scores relating to age, gender and ethnicity, but one study defined “cut-off” scores of less than 25.5kg for men and 18kg for women. Anything below those numbers suggested the presence of sarcopenia – age-related loss of muscle mass, strength and performance. (The average scores in a 2021 study were 35.2kg in men and 26.2kg in women.)

Not got a dynamometer? Don’t worry: some researchers question the relevance of measuring maximal grip strength, or in other words, the most force you can exert. “Our research suggests that a single maximal contraction may not be the most helpful measure to represent handgrip and upper-limb strength,” says Chueh-Ho Lin, associate professor in gerontology and long-term care at Taipei Medical University.

“Most daily activities require appropriate – and precise – grip strength over a prolonged period, rather than a brief contraction. For example, to drink from a mug or a soda bottle, you don’t need to squeeze it with all your force, you need only sufficient strength to hold on to it.”

Other research that Chueh-Ho Lin was involved in found that continuous grip strength declined more, and was less consistent, than maximal grip strength scores among older adults, a finding that would not be revealed by dynamometer testing.

Cole agrees: “In daily life, many of the grip actions we do are endurance-based – carrying shopping bags, turning a screwdriver, holding a tennis racquet for two hours.”

So what should we be doing to improve grip? “I would recommend repeated squeezing of an object at 80% or higher of your maximal ability, releasing each contraction with control,” says Lin. Cole suggests holding a 10kg weight plate in each hand for a minute, or wringing out a wet towel, holding the “squeeze” position for around 30 seconds. “Don’t be surprised if you find differences between your right and left hands – the ‘dominant’ hand is typically 10% stronger,” he says.

You don’t necessarily need to isolate grip strength to improve it. “Gym exercises with barbells and dumbbells, like dead lifts, farmer’s carry [where you hold a dumbbell in each hand, with arms straight and by your sides as you walk or stand still] and bicep curls will all challenge grip, as will bodyweight exercises such as dead hangs and pull-ups,” says Cole.

If your grip is feeble, strengthening it will have direct benefits – it might improve your tennis serve, raise your weight-training game or simply help you get to the pickled onions. But it might also serve as a helpful nudge that you need to get a grip on your overall physical capacity.