The Bout Cadence Method Improves the Quantification of Stepping Cadence In Free-Living Conditions

Abstract Background Existing analytical approaches used to measure free-living stepping cadence (steps per minute; spm) characterize stepping two-ways: 1) 60 s epochs without considering time spent stepping during the epoch (step accumulation; SA), or 2) a bout-based analysis that considers both number of steps and time spent stepping during stepping bouts (total event cadence; TEC). SA and TEC may incorrectly characterize cadence in epochs that do not consist of continuous stepping or if there are marked changes in cadence within a stepping bout, respectively. Research Question How does a bout-based analytical method that examines each stepping bout individually and considers within-bout changes in stepping cadence during epochs ≥120 s (Bout Cadence; BC) compare to SA and TEC? Methods ActivPAL™-derived data from 122 participants were analyzed (790 total days). SA and TEC were calculated according to previous literature. BC calculated cadence bout-by-bout and stride-by-stride for bouts lasting 140 spm were determined for each method. Time spent in slow (0–80 spm), medium (80–120 spm) and fast (>120 spm) cadences for each method were compared via Bland-Altman analyses. Results Almost half (43 %) of the total number of 60 s epochs included ≥2 stepping bouts, and 37 % of total stepping time was accumulated in continuous stepping bouts ≥120 s. Compared to TEC, BC identified more daily time spent in the 20–40 spm and >120 spm cadence bins, but less time spent in the 60−120 spm range. Both SA (fixed bias: -11.0 ± 12.4 min/day) and TEC (fixed bias: –10.0 ± 13.6 min/day) underestimated faster stepping cadences compared to BC. Significance Existing analytical approaches largely underestimate faster stepping cadences, resulting in inaccurate measurements of vigorous-intensity stepping activity. The BC better characterizes higher intensity stepping activity, which could have important implications for assessing participants’ true habitual stepping activity levels.