Abstract des Autors

The purpose of this study is to elucidate the blood lactate response in a simulation of the fifth section of the Hakone Ekiden (distance of 20.7 km) using a runner-motion-response type treadmill in a laboratory. Ten male subjects were divided into two groups : an experimental group (EG) of five long-distance runners, and a control group (CG) of five triathlon athletes. EG was asked to run at their desired speeds on a programmable treadmill whose "slope-setting" was changed automatically every fifty meters. The runners watched a video of the actual course during the experiment. CG performed treadmill running for a similar distance as EG on the basis of mean values obtained from running speeds by EG at a slope of zero percent. The running time for 20.7 km did not differ between EG and CG. At distances of 10.35, 16.2 and 20.7 km, the mean values of oxygen uptake were significantly higher in EG than that in CG. Changes in respiratory exchange ratio were similar to those of the oxygen uptake. The con-centrations of blood lactate for 10.35, 16.2 and 20.7 km were significantly higher in EG than in CG. These results suggest that most long-distance runners during the fifth section of the Ha-kone Ekiden are mainly supplied by the carbohydrate component, and blood lactate showed 4 mM or more at any point, with a higher intensity of physical activity during this section. Verf.-Referat