The pulpose of this study was to develop an apparatus system which could measure blood pressure and cardiac function during an isometric incremental handgrip exercise (IHG), and then distinguish whether the elevated blood pressure during IHG is caused by an increase of cardiac output or by an increase of peripheral vessel resistance. The study involved 27 healthy men who were aged between 23-73 years old. They attended this study as voluntary subjects and were divided into two groups, Y group and MO group, which were made up of their respective average ages (Y; age≦41.8years, MO; age over 41.8 years).
　They performed IHG at intensities of 12.5%, 25%, 37.5%, 50%, 62.5%, and 75% of maximum voluntary contraction (MVC) in a sitting position. IHG was measured in ten seconds of each percentage continuously, and was completed within 1 minute through all intensities. Cardiac output and arterial blood pressure were recorded on beat-by-beat basis during the IHG. The adequate data were gathered from 12 subjects, therefore the data analysis was carried out on the data of these 12 people. The systolic (SBP) and diastolic (DBP) blood pressures increased with intensity of exercise in a similar manner with the mean blood pressure (MBP) changes, in both groups. The arterial blood pressure response (CF-AP) during IHG was determined as the blood pressure change (△AP/Force) from 25% MVC to 62.5% MVC. It was indicated that CF-SBP, -DBP and -MBP were higher in MO group (n=6) than in Y group (n=6) and that the difference between both groups at CF-SBP was more remarkable than at CF-DBP and -MBP, but not significant. Cardiac output at rest in MO group resulted lower than in Y group, and significant changes were not observed during IHG in both groups. Total peripheral resistance (TPR) at rest was significantly higher in MO group than in Y group. TPR during IHG in Y group significantly increased at 75% MVC, and that in Mo group showed significant increase at 62.5% and 75% MVC.
　These results suggest that pressor response (CF-AP) during IHG was influenced by age due to the elevation of peripheral vessel resistance. It was concluded that the apparatus system developed in this study might have possibilities to clarify the factor of blood pressure response during IHG. It was also suggested that it is necessary to develop an apparatus which can measure more stable values of artery blood pressure and cardiac function on beat-by-beat basis during IHG, and to devise appropriate measurement conditions.

DESCENTE SPORTS SCIENCE Vol.25/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE