Purpose: This study aimed to examine the reliability and validity of the steep ramp test (SRT), a feasible, maximal exercise test on a cycle ergometer that does not require the use of respiratory gas analysis, in healthy children and adolescents.
Methods: Seventy-five children were randomly divided in a reliability group (n = 37, 17 boys and 20 girls; mean ± SD age = 13.86 ± 3.22 yr), which performed two SRTs within 2 wk, and a validity group (n = 38, 17 boys and 21 girls; mean ± SD age = 13.85 ± 3.20 yr), which performed both an SRT and a regular cardiopulmonary exercise test (CPET) with respiratory gas analysis within 2 wk. Peak work rate (WRpeak) was the main outcome of the SRT. Peak oxygen uptake (V˙O2peak) was the main outcome of the CPET. Reliability was examined with the intraclass correlation coefficient and a Bland and Altman plot, whereas validity was assessed using Pearson correlation coefficients and stepwise linear regression analysis.
Results: Reliability statistics for the WRpeak values attained at the two SRTs showed an intraclass correlation coefficient of 0.986 (P < 0.001). The average difference between the two SRTs was −6.4 W, with limits of agreement between +24.5 and −37.5 W. A high correlation between WRpeak attained at the SRT and the V˙O2peak achieved during the CPET was found (r = 0.958; P < 0.001). Stepwise linear regression analysis provided the following prediction equation: V˙O2peak (mL·min−1) = (8.262WRpeak SRT) + 177.096 (R2 = 0.917, SEE = 237.4).
Conclusion: The results suggest that the SRT is a reliable and valid exercise test in healthy children and adolescents, which can be used to predict V˙O2peak.