Cadence (steps/min) and intensity during ambulation in 6-20 year olds: The CADENCE-kids study

Background: Steps/day is widely utilized to estimate the total volume of ambulatory activity, but it does not directly reflect intensity, a central tenet of public health guidelines. Cadence (steps/min) represents an overlooked opportunity to describe the intensity of ambulatory activity. We sought to establish thresholds linking directly observed cadence with objectively measured intensity in 6-20 year olds.Methods: One hundred twenty participants completed multiple 5-min bouts on a treadmill, from 13.4 m/min (0.80 km/h) to 134.0 m/min (8.04 km/h). The protocol was terminated when participants naturally transitioned to running, or if they chose to not continue. Steps were visually counted and intensity was objectively measured using a portable metabolic system. Youth metabolic equivalents (METy) were calculated for 6-17 year olds, with moderate intensity defined as >/=4 and /=6 METy. Traditional METs were calculated for 18-20 year olds, with moderate intensity defined as >/=3 and /=6 METs. Optimal cadence thresholds for moderate and vigorous intensity were identified using segmented random coefficients models and receiver operating characteristic (ROC) curves.Result: Participants were on average (+/- SD) aged 13.1 +/- 4.3 years, weighed 55.8 +/- 22.3 kg, and had a BMI z-score of 0.58 +/- 1.21. Moderate intensity thresholds (from regression and ROC analyses) ranged from 128.4 steps/min among 6-8 year olds to 87.3 steps/min among 18-20 year olds. Comparable values for vigorous intensity ranged from 157.7 steps/min among 6-8 year olds to 119.3 steps/min among 18-20 year olds. Considering both regression and ROC approaches, heuristic cadence thresholds (i.e., evidence-based, practical, rounded) ranged from 125 to 90 steps/min for moderate intensity, and 155 to 125 steps/min for vigorous intensity, with higher cadences for younger age groups. Sensitivities and specificities for these heuristic thresholds ranged from 77.8 to 99.0%, indicating fair to excellent classification accuracy.Conclusions: These heuristic cadence thresholds may be used to prescribe physical activity intensity in public health recommendations. In the research and clinical context, these heuristic cadence thresholds have apparent value for accelerometer-based analytical approaches to determine the intensity of ambulatory activity.Peer reviewedCommunity Health Sciences, Counseling and Counseling Psycholog

Predicting Text Readability with Personal Pronouns

Part 5: Perceptual IntelligenceInternational audienceWhile the classic Readability Formula exploits word and sentence length, we aim to test whether Personal Pronouns (PPs) can be used to predict text readability with similar accuracy or not. Out of this motivation, we first calculated readability score of randomly selected texts of nine genres from the British National Corpus (BNC). Then we used Multiple Linear Regression (MLR) to determine the degree to which readability could be explained by any of the 38 individual or combinational subsets of various PPs in their orthographical forms (including I, me, we, us, you, he, him, she, her (the Objective Case), it, they and them). Results show that (1) subsets of plural PPs can be more predicative than those of singular ones; (2) subsets of Objective forms can make better predictions than those of Subjective ones; (3) both the subsets of first- and third-person PPs show stronger predictive power than those of second-person PPs; (4) adding the article the to the subsets could only improve the prediction slightly. Reevaluation with resampled texts from BNC verify the practicality of using PPs as an alternative approach to predict text readability