Author(s): YASUSHI, E., HONDA, S., SUGAWARA, H., Institution: UNIVERSITY OF TSUKUBA, Country: JAPAN, Abstract-ID: 2380

INTRODUCTION:
The contribution of aerobic energy supply during middle distance race is estimated more than 50% for 800 m and 70% for 1500m (Hill, 1998). However, physiological determinants related to aerobic and anaerobic capacities has not been clarified compared to long distance running (Brandon, 1995). Theoretically and practically to enhance performance of middle-distance running, it would be important to increase in aerobic energy supply during the race to save anaerobic capacity until the final stage of the race. Jones et al. (2008) showed the possibility of saving oxygen deficit in the first stage by rapid rise of oxygen uptake. The purpose was to examine rapid rise of oxygen uptake kinetics in early stage of supra maximal running and to propose the index of the evaluation of oxygen uptake kinetics for middle-distance runner.
METHODS:
15 male middle-distance runners are recruited as a subject for the study. They had two set of treadmill tests to estimate vVO2max and maximal accumulated oxygen deficit (MAOD) in July and November. At first VO2max for each subject was measured on a treadmill by means of all-out running test for about 4~5 min after 5 successive sets of incremental sub-maximal 3 min run about 14 to 18 km/h. MAOD test was conducted on a treadmill setting at 110 - 120 % of vVO2max until voluntary exhausted. Oxygen uptake was measured by bless-by-bless before 2 min start of running until all out. Time constant τ (VO2τ) and peak of VO2 were estimated to be fit exponential regression model. VO2A was calculated VO2peak divided by VO2τ.
RESULTS:
The average (SD) of 800 m and 1500 m velocities for the subjects were 24.6 (1.0) km/h and 21.8 (0.8) km/h in July and 24.6 (1.0) km/h and 22.4 (0.5) km/h in Nov, respectively. The average (SD) of VO2peak, VO2τ, and VO2A for the subjects were 60.6 (4.2) ml/kg/min, 16.7 (2.1) sec, 3.88 (0.45) ml/kg/min/sec in July and 61.6 (3.5) ml/kg/min, 16.8 (3.0) sec, 3.85 (0.70) ml/kg/min/sec in Nov. VO2τ and VO2A of the subjects were positive and negative correlated to their MAOD in July (r=0.75, p<0.01 and r=-0.83, p<0.01) and Nov (r=0.58, p<0.01 and r=-0.66, p<0.01). There are no significant relationships between the velocities of 800 m and 1500 m and VO2A. But we can find a tendency between changes in these velocities and change in VO2A (r=0.50 for 800 m and r=0.57 for 1500 m) from July to Nov.
CONCLUSION:
VO2τ is an index of oxygen uptake kinetics but influenced by VO2peak. The results showed that VO2A can evaluate not only for rapid rise of oxygen uptake but also for peak of oxygen uptake. There is negative relationship between change in VO2A and change in MAOD, which suggests that VO2A may be more appropriate index of aerobic ability for middle distance runner against anaerobic capacity evaluated by MAOD. It could be also shown that rapid rise of oxygen uptake kinetics is one of important aerobic capacity for middle distance runner.