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

ABSTRACT

PURPOSE: The aims of the present study were to investigate blood lactate kinetics following high intensity exercise and identify the physiological determinants of 800 m running performance. METHODS: Fourteen competitive 800 m 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. RESULTS: 800 m running performance was significantly correlated with peak oxygen consumption (r = -0.794), γ1 and γ2 at 800 m race pace (r = -0.604 and -0.845, respectively), and QLaA at maximal running speed (r = -0.657). V ˙ O2peak and γ2 at 800 m race pace explained 83% of the variance in 800 m running performance. CONCLUSION: 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 800 m 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.