Do Older Adults Achieve Moderate Intensity When Walking At Their Self-selected Pace?

Abstract

Walking at a cadence of ≥100 steps/min consistently corresponds to minimally moderate intensity physical activity (PA). While current PA guidelines emphasize the importance of PA intensity for positive health outcomes, most young adults already naturally walk at cadences ≥100 steps/min. It is unknown whether older adults select these same cadences and intensities when they freely select their walking pace. PURPOSE: To determine cadence and intensity of self-paced walking in older adults, and to evaluate the accuracy of using ≥100 steps/min to indicate moderate intensity in this population. METHODS: Twenty-six healthy, ambulatory older adults (10M,16W; mean±SD; age=68.3±4.8 years; height=1.67±.08 m; mass=73.4±12.3 kg) walked continuously for 5min at their self-selected pace back and forth along a 13m pathway that included a 7m gait mat. Oxygen uptake (VO2; mL/kg/min) was determined using indirect calorimetry and converted to absolutely-defined metabolic equivalents (METs; VO2/3.5). Average cadence was quantified using the gait mat. Prevalence of cadences ≥100 and METs ≥3 was calculated as the number of participants above the respective thresholds divided by total participants (n=26). Classification Accuracy (ACC; true positive + true negative / total participants) determined the accuracy of ≥100 steps/min indicating ≥3 METs. RESULTS: The majority of participants (23/26, 83.3%) walked at a cadence ≥100 steps/min (cadence=113±9 steps/min), and many (20/26, 76.9%) achieved moderate intensity (METs=3.43±0.59). A cadence of ≥100 steps/min was a strong indicator of moderate intensity during self-paced walking (i.e., ≥3 to <6 METs, ACC = 80.8%). CONCLUSION: Most healthy older adults attain at least moderate metabolic intensity during self-paced walking. These findings further suggest that “going for a walk” can be recommended, even in the absence of specific PA intensity guidelines. However, these results are preliminary and include only healthy, ambulatory, and relatively young (i.e., only one participant >75 years old) older adults. Future studies should continue to explore self-paced walking in a more representative sample of older adults, and include more of the oldest adults (i.e., >75 years), or those with disease or ambulatory limitations. FUNDING:NIH-NIA-5R01AG049024