REPRODUCIBILITY OF CARDIORESPIRATORY MEASUREMENTS DURING SUBMAXIMAL AND MAXIMAL RUNNING IN CHILDREN

With the increased use of oxygen consumption measurements in clinical and sporting studies, measurement variability has become more importan t to both the paediatric clinician and the sports scientist. In this s tudy we assessed the reproducibility of cardiorespiratory measurements during submaximal and maximal running in children. Ten healthy, physi cally active boys (mean(s.d.) age 10.7(0.71) years) performed two subm aximal and two maximal running tests within a 4 week period. The subma ximal protocol consisted of three 6 minute runs at 7.2, 8.0 and 8.8 km /h. Every attempt was made to minimize the sources of non-biological v ariability at each testing session. During submaximal exercise, oxygen consumption (VO2), heart rate (HR) and fractional utilization appeare d to be the most reliable measures accounting for over two-thirds of t he total variation (coefficients of reliability (CR) of 68%, 94% and 8 2% respectively). Ventilation (Ve) and respiratory exchange ratio (RER ) proved to be only moderately reliable accounting for less than half of the total variation (CR 50% and 45% respectively). At maximal exerc ise, VO2, Ve and time to exhaustion were most reliable, accounting for approximately two-thirds of the total variation (CR 65%, 63% and 63% respectively). Within this test environment, a two visit submaximal as sessment was capable of estimating VO2 with a standard error of +/-1.2 5 ml/kg/min. Similarly, for maximal testing a two visit assessment est imated peak VO2 with a standard error of +/-2.28 ml/kg/min. On the evi dence of these results a two visit assessment for submaximal and maxim al exercise testing seems adequate to estimate the stability of submax imal cardiorespiratory measures and peak VO2 in healthy, normally acti ve boys.