(August 2025) It’s well known that as we age, we progressively lose muscle. It’s equally well known that muscle loss and weakness in older adults increases the risk of several age-related diseases across every body system you can think of, from the heart and brain to the lungs, joints, and kidneys. These illnesses, in turn, increase the likelihood of hospitalisation, disability, and early death. The relationship appears to work in both directions: illness can accelerate muscle weakness, and muscle weakness can make illness more likely.
Doctors and researchers often assess muscle weakness using devices that measure grip strength. While these tools are widely used and informative, variations between different models can sometimes lead to inconsistent results. Interestingly, average grip strength can vary considerably across populations – for example, men aged 60-69 average 43kg in Europe, but only 28kg in South Asia.
The question was, then, whether a simpler, more standardised test of strength and consequent disease risk could also be found – one that would make research and risk prediction simple and comparable across any number of countries.
The First Large-Scale Study of the 5kg Test
Researcher Dr. Rizwan Qaisar and his colleagues at the University of Sharjah, United Arab Emirates, set out to find whether something as straightforward as lifting 5 kilograms – roughly the weight of a heavy grocery bag - could be such a measure. This is an easy enough test to perform in the home or in the clinic and can even be achieved with common household objects.
The study, published in Scientific Reports, was the first to test whether this simple metric could be plausibly used to assess the risk of age-related diseases in the way that grip strength has been historically used.
Using data from over 50,000 SHARE participants aged 50 and older across 15 European countries, they assessed whether this “5kg Test” could predict health outcomes as effectively as traditional grip strength measures. Notably, nearly one in five participants already struggled to lift 5 kilos at the start.
The 5kg Test Predicted Both Physical and Mental Health
Over the next four years, participants who had difficulty lifting 5 kilos faced a noticeably higher risk of several conditions. The strongest associations were with:
- Lower quality of life
- Symptoms of depression
- Osteoarthritis of the knee joint
Additionally, these respondents exhibited mild to moderate risks for developing rheumatoid arthritis, heart attack, hypertension, Alzheimer’s disease, stroke, or hip fracture.
A Gender Divide After 65
The risks were especially pronounced for men over 65. Since men generally begin with stronger muscles, difficulty lifting 5 kilos at that age signals a sharper decline compared to women of the same age.
Quality of Life Takes the Hardest Hit
Among all the outcomes studied, poor quality of life and symptoms of depression showed the strongest links to difficulty lifting 5 kilograms. Using the internationally recognised CASP12 survey — which measures autonomy, control, pleasure, and self-realisation — researchers found that weaker participants consistently scored lower on the quality of life scale.
This finding underscores that muscle health is about much more than strength. It underpins independence, confidence, and the ability to enjoy daily life.
A Simple Screening Tool
Perhaps the most important takeaway is that such a basic test could serve as an early warning system. Simply asking whether someone can lift 5 kilos may help flag older adults at risk long before more serious health problems appear.
It’s not a replacement for medical tests, but it offers a quick, inexpensive, and user-friendly way to spot potential concerns in clinics, community programs, or even at home.
Study by Qaisar, R., Hussain, M.A., Franzese, F. et al. The simple task of lifting five kilograms serves as a predictor of age-related disorders in old adults. Sci Rep 15, 17833 (2025).
URL: https://doi.org/10.1038/s41598-025-03128-y
Picture: © Adobe Stock / Rido
