International normative 20 m shuttle run values from 1 142 026 children and youth representing 50 countries

Objective To develop sex-specific and age-specific international norms for the 20 m shuttle run test (20mSRT) in children and youth (aged 9-17 years), and to estimate the prevalence meeting the FITNESSGRAM criterion-referenced standards for healthy cardiorespiratory endurance (CRE). Methods A systematic review was undertaken to identify papers explicitly reporting descriptive 20mSRT (with 1 min stages) data on children and youth since 1981. Data were included on apparently healthy (free from known disease/injury) 9-17 years old. Following standardisation to a common metric and for protocol differences, pseudo data were generated using Monte Carlo simulation, with population-weighted sex-specific and age-specific normative centiles generated using the Lambda Mu and Sigma (LMS) method. Sex-related and age-related differences were expressed as per cent and standardised differences in means. The prevalence with healthy CRE was estimated using the sex-specific and age-specific FITNESSGRAM criterion-referenced standards for (V)over dotO(2peak). Results Norms were displayed as tabulated centiles and as smoothed centile curves for the 20mSRT using 4 common metrics (speed at the last completed stage, completed stages/minutes, laps and relative (V)over dotO(2peak)). The final data set included 1 142 026 children and youth from 50 countries, extracted from 177 studies. Boys consistently outperformed girls at each age group (mean difference +/- 95% CI: 0.86 +/- 0.28 km/h or 0.79 +/- 0.20 standardised units), with the magnitude of agerelated increase larger for boys than for girls. A higher proportion of boys (mean +/- 95% CI: 67 +/- 14%) had healthy CRE than girls (mean +/- 95% CI: 54 +/- 17%), with the prevalence of healthy CRE decreasing systematically with age. Conclusions This study provides the most comprehensive and up-to-date set of international sexspecific and age-specific 20mSRT norms for children and youth, which have utility for health and fitness screening, profiling, monitoring and surveillance.