同一負荷運動に対する中高年者の10年後の呼吸循環応答(創立25周年記念特集号-スポーツ科学の諸問題-)

Effect of aging on circulatory responses to given work load were investigated in middle-aged and older individuals. Seven males and six females ranging in age from 48 to 77 years old (mean : 59.7) were studied. Measurements for heart rate, blood pressure, respiratory rate, ventilatory volume and oxygen intake were performed during 12 min. exercise on a bicycle ergometer consisting of 4 min. exercise at 150, 300 and 450 kgm/min in 1980 and 1990. The major results were as follows. 1) Left grip strenth were found decreased more than right one after 10 years of aging. 2) As for the effects of aging on circuratory function during exersise, the increase of systolic blood pressure were greater than heart rate. 3) Rate-pressure product (systolic blood pressure x heart rate) were found increased in older individuals. 4) Oxygen requirement of the same work load was not affected by aging. Their ventilatory volume were increased with aging, but respiratory rate during the exercise did not change which resulted in increase of tidal volume (tidal volume : ventilatory volume/respiratory rate). 5) These results suggest that respiratory efficiency of older individuals remarkably decrease because of lesser oxygen removal