How fast an older person walks – their ‘gait speed’ – has been used as a proxy for health for decades. Whether or not they can get out of a chair quickly, how long it takes them to cross a room – are measures of their physical function.
It makes sense that it’s a health indicator, because walking actually takes a lot of unconscious work; your muscles, brain and nervous system all have to act together to make it happen. But is it just older people who reveal tell-tale signs about their health when they walk? Maybe not.
In this paper, scientists used data from the long-running Dunedin Study, which has followed more than a thousand New Zealanders from birth through to age 45. The latest series of tests these people did measured how quickly they walked, both as a singular act and while doing something that’s cognitively challenging (reciting alternate letters of the alphabet). They also measured 19 different biomarkers – things like cholesterol level and heart rate – which gave an indicator of the person’s biological age as opposed to their chronological age.
What does your walk say about your health?
For example, they could be 45 years old but have poor biomarkers that made them look more like a 48-year-old. The final thing the researchers measured was how old people looked – tested by an independent team of face-raters. Scary stuff!
By doing all of these measurements, and by completing brain scans and cognitive tests of each patient, the researchers could draw comparisons between how fast people walked and how healthy they were. They found that the fastest walkers were the healthiest, and the slowest walkers tended to look older, have poor biomarkers, and also had signs of ageing in their brain.
Another interesting finding was that cognitive ability seemed to persist through time. The people who had poorer cognition aged three were also slower walkers at 45 and still had poorer cognitive ability, though the researchers aren’t quite sure why this is or what it means.
Gait speed, previously thought to be a helpful test only in older people, could be a quick, useful indicator of how healthy someone is. If you’re slowing up without a particular reason, it might be a sign that you need to get back into exercise or switch up the diet. Looking in the mirror to see if you look older than you actually are works too – though that’s a more terrifying prospect for some.