How Fast Do You Walk?

There’s little doubt that, as we get older, we tend to slow down.  And this is probably most obvious in our walking speed.  It’s an indication of vitality.  But is it also an indicator of how our life-span may be shortening?  That’s the subject of a study done at the University of Pittsburgh, and published in the Journal of the American Medical Association. 

The researchers performed a meta-analysis of 9 studies of groups of people over 65 who were followed for an average of 12 years.  There were 17,500 individuals in the study; their average age was 73.5 years, 60% were women, and 80% were white.  Gait speed was measured at baseline, and survival rate was analyzed in the pooled analysis, after adjustments for height, race, body mass index (BMI), smoking history, systolic blood pressure, chronic diseases, hospitalizations, and self-reported health. 

The survival rates at 5 and 10 years were 85% and 60%.  Gait speed was significantly associated with survival in all 9 studies and in the pooled analysis.  The overall average gait speed was 0.92 m/s (meters per second), or 2.06 mph.  Each 1-m/s increase (2.24 mph increase) was linked to a 12% relative reduction in the risk of death during the follow-up period.

Further analysis showed that gait speed added predictive value for mortality beyond  that provided by age and sex alone;  this was equivalent to the predictive value based on age, sex, use of mobility aids, chronic conditions, smoking history, blood pressure, BMI, and hospitalization.

Of course,  the question most people will ask is: “can I improve my chances of living longer by raising my gait speed?”  The study didn’t answer this – indeed, it wasn’t designed to do so.  Such a study would require large numbers, monitored interventions, and a control group.  However, there’s little doubt (and plenty of evidence to show) that physical exercise per se will improve life span.  So if you’re not walking or otherwise exercising now, I’d advise starting.  It may not make you live longer, but it will certainly make the rest of your life healthier and improve your chances it will be disease-free for longer.