Cadence-pace Conversion Tool For Runners: The SKyRoCKeT Study

PURPOSE: Pace is the time it takes to walk/run a known distance and is expressed in min/mile or min/km units. We propose that cadence (steps/min) can be used as a proxy for pace and can be further adjusted using height. METHODS: As part of the larger NIH-funded SKyRoCKeT study, 44 participants (18-20 years of age, 38.6% female) performed treadmill exercise ranging in speed from 0.8-9.7 km/h increased incrementally by 0.8 km/h in 5-min bouts. They produced 472 complete bouts containing at least one running bout (defined as a speed of ≥6.4 km/h and a cadence ≥140 steps/min). Cadence was directly observed (video back up). Height was measured with stadiometer. Due to potential nonlinearity of the association between the explanatory variables (height and cadence) and response variable (log(pace)), a more adaptive linear regression with splines was explored. Log(pace) was used to reduce the influence on regression results of outlying large paces at lower cadences. RESULTS: Mean height was 171.2 cm (sd = 9.4). Cadence ranged 31.8-169 steps/min, and paces ranged 6.2-74.6 min/km, across the 12 increasing speeds. A cubic spline for cadence and quadratic spline for height were found significant (p < 0.0118), with no substantial enhancement from higher order polynomials for either variable. Removing either variable yielded substantially inferior models. The model yielded an adjusted R-squared of 0.9328 (p < 0.0001). An interactive 3-dimensional surface graph was created in R (with curves for heights of 160, 170, and 180 cm) was produced to predict one’s cadence for any given height and pace CONCLUSIONS: Pace is jointly and negatively related to both cadence and height, with decreased pace as height and cadence increase. Using the created tool, we can predict that an individual with a height of 170 cm would perform a 8.5 min/km pace at 134 steps/min, 8 min/km at 140 steps/min, and 7.5 min/km at 148 steps/min. This preliminary analysis provides promise that the utility of this tool can be enhanced with additional data representing greater individual heights, speeds, and cadences. This tool has the potential to aid runners in preparing for and during competitive races, as well as those who simply wish to monitor their performance, to maintain and achieve their pace goals. Supported by: NICHD-R01HD105768