Influences of Age and Sex on Cardiac Output during Submaximal Exercise

抄録

Cardiac output (Q) was determined by the CO₂ rebreathing method in 85 Japanese subjects, from 10 to 55 years of age, during submaximal exercise. Q for adult females was not signifi-cantly different from that for adult males. Values of Q for boys, girls, and older adult males were significantly lower than that for the younger adult males at a given oxygen uptake (Vo₂) level. The relationship between Q at 1.0 l/min Vo₂ (Q_1.0) and body weight was examined for all the available data including those for various foreigu populations in literature. It was found that the groups with a large body weight tended to have a high value of Q. Thus, body size in some way influences Q during submaximal exercise even when metabolic levels are identical, and the differences in Q between males and females or adults and children are thought to be closely related to differences in body size. Although siguificant correlation was found between Q_1.0 and body size for all subjects in this study, older adult males had comparatively lower Q for their body size. The cardiovascular system of middle-age people is considered to differ from that of the younger persons.