Effects of prolonged kendo practice in a hot environment on cardiovascular function.
- VernacularTitle:高温環境下における長時間の剣道稽古に伴う脱水が血行動態および左心機能に及ぼす影響
- Author:
TAKAHIRO WAKU
;
MITSUO MATSUDA
;
ICHIRO KONO
;
SHUKOH HAGA
;
YASUKO MIWA
;
MAKOTO ENDO
;
TAKASHI MIYAUCHI
;
HARUO IKEGAMI
- Publication Type:Journal Article
- Keywords:
kendo;
hot environment;
dehydration;
hemoconcentration;
cardiovascular function
- From:Japanese Journal of Physical Fitness and Sports Medicine
1991;40(5):465-474
- CountryJapan
- Language:Japanese
-
Abstract:
To study the effects of prolonged kendo practice in a hot environment on cardiovascular function, certain hemodynamic parameters were measured in 5 male college kendo fencers before and after 1 hour of kendo practice performed at a dry bulb temperature of 30.4t and wet bulb temperature of 26.2°C After kendo practice, body weight was significantly decreased and both hematocrit and blood viscosity were significantly increased. The left ventricular end-diastolic dimension and the left atrial dimension, measured by echocardiography, were significantly reduced after kendo practice, and stroke volume, ejection fraction, and fractional shortening were also significantly decreased after practice. The same fencers were subjected to lower body negative pressure testing designed to reduce the left ventricular end-diastolic dimension to the same degree as kendo practice, and comparable decreases in stroke volume, ejection fraction, and fractional shortening were observed. The ratio of end-systolic wall stress to end-systolic volume index was significantly increased during both kendo practice and lower body negative pressure testing. We conclude that prolonged kendo practice in a hot environment impairs cardiac pump function by reducing preload in parallel with the decrease in venous return, that myocardial contractility may not deteriorate despite marked hemoconcentration, and that fluid intake during practice may prevent deterioration of cardiovascular function.
