Small Increases in Physical Activity Produce Meaningful Benefits in Older Adults
Studies of physical activity in older people have long demonstrated that, at the lower end of the dose-response curve, even small increases in the amount of activity produce meaningful benefits. While human studies can only show correlations between exercise and health, animal studies fill in the gap to show causation. Being sedentary is bad for your health, but being even a little less than sedentary is meaningfully less bad for your health. Small increases in physical activity are not irrelevant when the overall level of physical activity is low. The study noted here reinforces this point.
Walking cadence has been suggested as a measure of activity intensity; however, it remains uncertain if prefrail and frail older adults can increase their walking cadence and if doing so leads to improvements in functional capacity. We aimed to determine if cadence can be increased and if this leads to improvement in functional capacity in prefrail and frail older adults. We performed a secondary data analysis of a walking intervention in prefrail and frail older adults living in retirement communities. Patients were randomized to Casual Speed Walking (CSW) and High-Intensity Walking (HIW) groups. Our primary outcome was improvement in 6-minute walk test distance above the minimally clinical important difference.
102 participants were included in the final analysis with 56 in the CSW group and 46 in the HIW group. Participants in the HIW group increased their walking cadence as compared to the CSW group during the intervention (HIW averaged 100 steps/min vs. CSW averaged 77 steps/min). Participants that increased their walking cadence demonstrated an increased odds of improvement in their 6-minute walk test minimum clinically important difference (odds ratio: 0.11). Older adults can increase their walking cadence and walking cadence can serve as a surrogate measure of activity intensity during walking interventions. An increase of 14 steps/minute from their comfortable walking cadence increased the odds of improvement in 6-minute walk test.
