Grip strength

Grip strength is how hard you can squeeze, measured with a hand dynamometer in kilograms. It is one of the simplest measurements in medicine and one of the most informative.

Its value is as a proxy. Grip correlates with total body strength and with muscle quality generally, so a cheap squeeze test stands in for a whole battery of assessments that would take an hour and a laboratory.

The outcome data are striking. In half a million UK Biobank participants, every 5 kg of lower grip strength was associated with roughly 16 to 20% higher all cause mortality, along with higher cardiovascular, respiratory and cancer risk, and it added predictive value to an established risk score.

It is also now central to how sarcopenia is diagnosed. The revised European consensus made low muscle strength the primary criterion, ahead of muscle size, because strength predicts outcomes better than mass does, and grip is the practical way to measure it.

The obvious misreading is to train your hands. Grip is a marker of the system rather than a lever on it, so squeezing a rubber ball does not buy you the associated outcomes. What does is whole body resistance training, which improves grip as a by-product.

That said, grip does limit certain lifts, and a grip that fails before your back does on a deadlift is worth training directly with carries, holds and heavier pulling.

In practice, treat a dynamometer reading as one of the few numbers worth tracking across decades, and train it the way you train everything else: by lifting heavy things regularly.

Sources

• Celis-Morales CA, et al. Associations of grip strength with cardiovascular, respiratory, and cancer outcomes and all cause mortality: prospective cohort study of half a million UK Biobank participants. BMJ 2018;361:k1651
• Cruz-Jentoft AJ, et al. Sarcopenia: revised European consensus on definition and diagnosis (EWGSOP2). Age Ageing 2019;48:16-31