Cadence (steps/min) and relative intensity in 61 to 85-year-olds: the CADENCE-Adults study.
Level 4 - case-series / case-control
Cross-sectional laboratory calibration and diagnostic threshold study.
PubMed 38031156 · doi:10.1186/s12966-023-01543-w
What was done
Ninety-seven ostensibly healthy adults aged 61 to 85 years (mean age 72.7 ± 6.9 years; 49.5% women) completed up to nine 5-minute treadmill walking stages starting at 0.5 mph (0.8 km/h) and increasing in 0.5 mph increments with 2-minute rest intervals between bouts. Direct-observed steps were hand-counted from video recordings. Heart rate (HR) was recorded via a chest monitor, and Borg Rating of Perceived Exertion (RPE) was self-reported during the final minute of each stage. Segmented mixed-model regression and Receiver Operating Characteristic (ROC) curve analyses were used to determine cadence thresholds corresponding to relatively defined moderate (≥64% HR max, ≥40% HR reserve [HRR], or RPE ≥12) and vigorous (≥77% HR max, ≥60% HRR, or RPE ≥14) intensities.
What was found
For moderate-intensity indicators, optimal cadence thresholds ranged from 105.9 to 112.8 steps/min with segmented regression and from 102.0 to 104.3 steps/min with ROC analyses, yielding an overall heuristic threshold of ≥105 steps/min. For vigorous-intensity indicators, optimal cadences ranged from 126.1 to 132.1 steps/min with segmented regression and from 106.7 to 116.0 steps/min with ROC analyses. The resulting heuristic threshold for vigorous intensity was identified as ≥115 steps/min for greater sensitivity or ≥120 steps/min for greater specificity.
Why it matters
These findings establish practical, step-rate-based heuristic targets (≥105 steps/min for moderate intensity and ≥115–120 steps/min for vigorous intensity) that align with relative physiological effort and perceived exertion in older adults.
Limits
The study was conducted on 97 healthy older adults in a controlled laboratory treadmill protocol, which may not translate directly to free-living overground walking. HR max was calculated using an age-based estimation formula (220 − age) rather than measured directly via maximal cardiopulmonary exercise testing. The sample excluded adults with significant functional limitations or those taking medications that alter heart rate responses.
Cited by
- supports Vigorous-intensity physical activity is defined as greater than 6 METs or 7 to 8 on a 10-point perceived exertion scale.