出版社:Japan Society of Physical Education, Health and Sport Sciences
摘要:The purpose of this study was to analyze how cardiac output varies in exercise. The experiment was conducted to reveal the relationship between physical endurance running time measured by treadmill and the cardiac output by acetylene method. Heart rate, oxygen consumption and cardiac output were observed at the point of l,2,3,4,......minutes until the exhaustion during the running on the treadmill with slope of 8.6% and speed of 180m/min. For analysis of sample gas, a modified Haldane gas analyzer was used. It was found that cardiac output per minute per unit body surface of 8 normal subjects at rest was 2.30l/min/m^2 in average. This value is in close agreement with data observed by Grollman and Katsuki, while it is lower than those by Asmussen, Astrand Mitchell. It is found that the heart rate is increased to the same highest level in all and subjects during the maximal work, while the cardiac output or stroke volume per body weight is greater in the subjects whose endurance running time is longer. It is suggested from these results that cardiac output was considered one of the most important factors of maximal working capacity of aerobic nature.