Cadence-based Classification of Minimally Moderate Intensity During Overground Walking in 21- to 40-Year-Old Adults

Abstract

Background: A walking cadence of ≥100 steps/min corresponds to minimally moderate intensity, absolutely defined as ≥3 metabolic equivalents (METs). This threshold has primarily been calibrated during treadmill walking. There is a need to determine the classification accuracy of this cadence threshold to predict intensity during overground walking.

Methods: In this laboratory-based cross-sectional investigation, participants (N = 75, 49.3% women, age 21-40 y) performed a single 5-minute overground (hallway) walking trial at a self-selected preferred pace. Steps accumulated during each trial were hand tallied and converted to cadence (steps/min). Oxygen uptake was measured using indirect calorimetry and converted to METs. The classification accuracy (sensitivity, specificity, overall accuracy, and positive predictive value) of ≥100 steps/min to predict ≥3 METs was calculated.

Results: A cadence threshold of ≥100 steps/min yielded an overall accuracy (combined sensitivity and specificity) of 73.3% for predicting minimally moderate intensity. Moreover, for individuals walking at a cadence ≥100 steps/min, the probability (positive predictive value) of achieving minimally moderate intensity was 80.3%.

Conclusions: Although primarily developed using treadmill-based protocols, a cadence threshold of ≥100 steps/min for young adults appears to be a valid heuristic value (evidence-based, rounded, practical) associated with minimally moderate intensity during overground walking performed at a self-selected preferred pace.

Trial registration: ClinicalTrials.gov NCT02650258.

Keywords: accelerometry; guidelines and recommendations; pedometry; physical activity.

Figures

Figure 1.

Scatter plot of cadence (steps/min) and intensity (metabolic equivalents [METs]) values observed during overground walking at a self-selected preferred walking pace. The shapes of the data points represent the classification of bouts as true positives (open circles), true negatives (open triangles), false positives (squares with cross), and false negatives (open squares). The dotted line signifies absolutely defined minimally moderate intensity (≥3 METs). The dashed line represents the heuristic moderate-intensity cadence threshold (≥100 steps/min).