Identifying physiological determinants of 800m running performance using post-exercise blood lactate kinetics.

Abstract

The aims of the present study were to investigate blood lactate kinetics following high intensity exercise and identify the physiological determinants of 800m running performance. Fourteen competitive 800m runners performed two running tests. First, participants performed a multistage graded exercise test to determine physiological indicators related to endurance performance. Second, participants performed four to six 30-s high intensity running bouts to determine post-exercise blood lactate kinetics. Using a biexponential time function, lactate exchange ability (γ1), lactate removal ability (γ2), and the quantity of lactate accumulated (QLaA) were calculated from individual blood lactate recovery data. 800m running performance was significantly correlated with peak oxygen consumption (r = -0.794), γ1 and γ2 at 800m race pace (r = -0.604 and -0.845, respectively), and QLaA at maximal running speed (r = -0.657). O2peak and γ2 at 800m race pace explained 83% of the variance in 800m running performance. Our results indicate that (1) a high capacity to exchange and remove lactate, (2) a high capacity for short-term lactate accumulation and, (3) peak oxygen consumption, are critical elements of 800m running performance. Accordingly, while lactate has primarily been utilized as a performance indicator for long-distance running, post-exercise lactate kinetics may also prove valuable as a performance determinant in middle-distance running.