The PWC170: comparison of different stage lengths in 11–16 year olds

It is unknown how the estimation of aerobic fitness in children and adolescents compares among physical working capacity (PWC) protocols with different stage lengths. The purpose of this study was twofold: (1) compare PWC tests with 2-, 3-, and 6-min stage lengths in youth, and (2) examine the relationship between PWC at a heart rate (HR) of 170 beats min⁻¹ (PWC170) and peak oxygen consumption (VO₂peak). Fifty youth (31 m, 19 f), aged 11–16 years participated. Each participant visited the laboratory twice and performed three PWC tests (2-, 3-, 6-min stages) on a cycle ergometer. Tests usually consisted of three stages of increasing loads with the goal of reaching HR ≥ 165 beats min⁻¹. Individual regression lines were created to predict workload at HR = 170 beats∙min⁻¹ for each test. Participants completed two VO_2peak tests, both running and cycling. Repeated measures ANOVA was used to compare PWC170 values. Pearson correlation was used to assess the relationships between VO_2peak and power output for different PWC170 stage lengths. The three PWC170 protocols differ significantly; therefore, it is not advisable to directly compare results from different protocols. Furthermore, PWC170 showed moderate associations with VO_2peak, with the 2-min protocol showing the best correlation.