Moderate-intensity stepping in older adults: insights from treadmill walking and daily living
Thomas Yates, Joseph Henson, Philip McBride, Benjamin D. Maylor, Louisa Herring, Jack A. Sargeant, Melanie J. Davies, Paddy C. Dempsey, Alex V. Rowlands, Charlotte L. Edwardson
Abstract
Abstract Background A step cadence of 100 steps/minute is widely used to define moderate-intensity walking. However, the generalizability of this threshold to different populations needs further research. We investigate moderate-intensity step cadence values during treadmill walking and daily living in older adults. Methods Older adults (≥ 60 years) were recruited from urban community venues. Data collection included 7 days of physical activity measured by an activPAL3™ thigh worn device, followed by a laboratory visit involving a 60-min assessment of resting metabolic rate, then a treadmill assessment with expired gas measured using a breath-by-breath analyser and steps measured by an activPAL3™. Treadmill stages were undertaken in a random order and lasted 5 min each at speeds of 1, 2, 3, 4 and 5 km/h. Metabolic equivalent values were determined for each stage as standardised values (METS standard ) and as multiples of resting metabolic rate (METS relative ). A value of 3 METS standard defined moderate-intensity stepping. Segmented generalised estimating equations modelled the association between step cadence and MET values. Results The study included 53 participants (median age = 75, years, BMI = 28.0 kg/m 2 , 45.3% women). At 2 km/h, the median METS standard and METS relative values were above 3 with a median cadence of 81.00 (IQR 72.00, 88.67) steps/minute. The predicted cadence at 3 METS standard was 70.3 (95% CI 61.4, 75.8) steps/minute. During free-living, participants undertook median (IQR) of 6988 (5933, 9211) steps/day, of which 2554 (1297, 4456) steps/day were undertaken in continuous stepping bouts lasting ≥ 1 min. For bouted daily steps, 96.4% (90.7%, 98.9%) were undertaken at ≥ 70 steps/minute. Conclusion A threshold as low as 70 steps/minute may be reflective of moderate-intensity stepping in older adults, with the vast majority of all bouted free-living stepping occurring above this threshold.