Walking pace, like grip strength, is one of the simple measures used by physicians to assess the progression of frailty in old age. Researchers here report on epidemiological data that shows an association between life expectancy and walking pace, in that older individuals who walk more slowly tend to have a shorter life expectancy. This is only to be expected: a slower pace tends to arise due to the presence of chronic age-related disease, lack of fitness, and in general a higher burden of cell and tissue damage, all of which are known to lead to a greater mortality risk.
People who report that they have a slower walking pace have a lower life expectancy than fast walkers. The research, using data from the UK Biobank of 474,919 people recruited within the UK, found those with a habitually fast walking pace have a long life expectancy across all levels of weight status - from underweight to morbidly obese. Underweight individuals with a slow walking pace had the lowest life expectancy (an average of 64.8 years for men, 72.4 years for women). The same pattern of results was found for waist circumference measurements. This is the first time research has associated fast walking pace with a longer life expectancy regardless of a person's body weight or obesity status.
"Our findings could help clarify the relative importance of physical fitness compared to body weight on life expectancy of individuals. In other words, the findings suggest that perhaps physical fitness is a better indicator of life expectancy than body mass index (BMI), and that encouraging the population to engage in brisk walking may add years to their lives. Studies published so far have mainly shown the impact of body weight and physical fitness on mortality in terms of relative risk, for example a 20 per cent relative increase of risk of death for every 5 unit BMI increase, compared to a reference value of a BMI of 25 (the threshold between normal weight and overweight). However, it is not always easy to interpret a "relative risk". Reporting in terms of life expectancy, conversely, is easier to interpret and gives a better idea of the separate and joint importance of body mass index and physical fitness."