VALIDITY OF INTERMITTENT ENDURANCE INDICATORS FOR RUGBY FOOTBALL PLAYERS

Abstract

The purpose of this study was to examine the validity of indicators evaluating intermittent endurance with high power output required in rugby football games. Eleven collegiate rugby football players performed an incremental exercise test into exhaustion on a cycle ergometer to determine VO2max, VO2AT and VO2 at the respiratory compensation point (RCP). The subjects also performed an intermittent exercise test on the cycle ergometer, consisting of twenty 5-s maximal effort exercise with 20-s recovery periods and the power output (W/kg) was measured. The absolute power decline and its rate (%decline) were calculated by dividing the average power output from the 9th to the 20th trials by that of the first trial. Correlations of VO2max, VO2AT and VO2RCP to the power output were higher (p < .05) in the middle and the last phases during the intermittent exercise test, while no significant correlations were observed the beginning phase. These results indicate that not only the aerobic energy supply system but also muscle metabolic and buffering capacity contribute to the maximal intermittent exercise with high intensity. Moderate correlation coefficients were found between RCP-% VO2max and decline (r = 0.69), and 0.67 for VO2RCP with %decline, 0.66 for RCP-%VO2max with %decline. Consequently, it is inferred that the RCP indicators (VO2RCP, RCP-%VO2max) are valid to measure the intermittent endurance with high power output requiring in the maximal intermittent exercise with high intensity in rugby games.