Can grip strength predict how long you will live?
Grip strength is one of the better-supported predictors of premature death: the lower it is, the higher the risk. It is a useful health indicator, but not yet evidence that training your grip strength directly extends your lifespan.
Grip strength is surprisingly strongly linked to how long you live. In an international study of nearly 140,000 people from 17 countries, every 5 kg reduction in grip strength was associated with an approximately 16% higher risk of death. In that study, grip strength was an even better predictor of death than blood pressure. A separate British study of more than 500,000 participants confirmed this: women with low grip strength had up to 20% greater chance of dying in the following seven years.
The association extends beyond premature death. Low grip strength is also linked to a higher risk of death from cardiovascular disease and lung conditions such as COPD. The link with cancer mortality is weaker and does not apply to all types of cancer.
There is an important nuance, however. In a Brazilian study, grip strength on its own was not a statistically significant predictor of death. Muscle power -- that is, strength combined with speed of movement -- was, however, and strongly so: people in the lowest group had almost six times the risk of dying compared with people in the highest group. Grip strength therefore captures part of the picture, but not all of it.
Beyond mortality, grip strength also predicts other problems: physical limitations, bone fractures, cognitive decline and hospital complications, especially in older age. Normal values are, incidentally, person-specific. Men peak at around 51 kg (from the late twenties to the late thirties), women at around 31 kg. After that, strength gradually declines. At age eighty, roughly a quarter of the population has a grip strength that is considered weak.
It is important to recognise that all of these associations are just that -- associations. Grip strength reflects how fit your body currently is, but it is not a direct cause of premature death. Someone with a chronic illness or poor overall health will generally also have lower grip strength. Whether improving your grip strength itself extends lifespan cannot be determined from these studies.
Based on two large prospective cohorts (UK Biobank n>500,000; PURE n≈140,000 from 17 countries), supplemented by a Brazilian cohort study (CLINIMEX) and multiple review studies on normal values and related outcomes. All associations are observational; causality has not been established.