暑熱環境における剣道稽古が血液流動性に及ぼす影響

Physical exercise in high temperature environments is known to cause a decrease in blood fluidity due to water loss from sweating. Those who train in Kendo wear thickly training wear and protective armor (Bogu) to prevent injuries when fighting with bamboo swords (Shinai) armed opponents. Because this gear prevents cooling down body temperature, it is believed to cause negative effects upon the kendo practitioner's physiology. Therefore, the purpose of our research is to examine the effect of water intake upon the blood fluidity and platelet aggregation of kendo practitioners. The subjects of our research were 7 healthy male kendo practitioners in ages 23.4±0.8. We conducted a randomized crossover trial. One group consumed 500 ml of water, while the other group did not consume anything. All subjects practiced kendo in high temperature environments (Wet Bulb Globe Temperature: WBGT: 27°C). An MC-FAN was used in order to measure fluidity. A PA-20 was utilized to test platelet aggregation. In our results, we noticed a significant decrease in blood fluidity in both groups following kendo practice. At 30 minutes after kendo practice, both groups had recovered, but the level of recovery by the group which had consumed water was significantly higher. The platelet aggregation in particular was greatly affected. It was suggested that the influence on blood fluidity and platelet aggregation were a reaction of the sympathetic nervous system. In conclusion, our findings suggest that water intake under exercise has an effect upon the recovery of decreased blood fluidity.