Ventilatory threshold, heart rate deflection point and middle distance running performance.

Physiological measures of performance capacity have traditionally centered around the measurement of maximal oxygen uptake (VO2max). This study examined the relationship between maximal and submaximal laboratory measures of performance and running times within a group of trained middle distance runners. Analysis of the data obtained from 10 male and 2 female athletes identified the running velocity corresponding to the Ventilatory Threshold [(VT) (mean +/- SD = 15.3 +/- 2.36 km.h-1. treadmill speed)] as the major correlate with 3000 m (r = -0.984, n = 12) running performance. Treadmill speed corresponding with the heart rate deflection point [(Vd) (mean +/- SD = 16.75 +/- 2.38)] and the VO2max (mean +/- SD = 55 +/- 6 ml.kg-1.min-1) was also highly correlated (r = 0.94 and r = 0.82 respectively, n = 12) with 3000 m running performance. The running velocity corresponding with VT alone explained 96.3% of the variance in 3000 m performance time. The addition of VO2max and Vd using multiple regression analysis did not further improve significantly the predictive value of the physiological measures. The results of this study support the laboratory estimation of physiological measures such as Vd and VT in the assessment of middle distance running performance.