Abstract
Effect of Exercise and Blood Volume on Plasma Volume ShiftKawabata T., T. Suzuki and T. MiyagawaDept. of Sport Medicine, Osaka City University School of MedicineThe aim of the present study is to assess the effect of exercise and BV on PV shift in individual variations. Thirteen well trained subjects participated in this study. BV, cardiac output and stroke volume were measured by the pulse dye densitometry using dye Indocyanine green. Subjects ran on the treadmill until exhaustion. Lactate threshold (LT), as a predictor of aerobic work capacity, was calculated from the exercise intensity at the point of plasma lactate concentration buildup to 4 mmol. Peak VO2, mean values (SEM), was 61.5(1.1) ml/kg/min. BV and PV were 64.7(3.9) and 38.1(2.4) ml/kg. The relationship of peak VO2 with BV and PV indicated a significant positive correlation. VO2 at LT was 57.5(1.5) ml/kg/min. The relationship of VO2 at LT with BV and PV indicated a significant positive correlation. The percentage of changes in PV during graded exercise decreased gradually from 10.7% to 20.7% in exhaustion. Shift in PV at LT level averaged 16.4% and the range of PV shift in individual variations were from 12.5% to 19.6%. The relationship of the changes in PV at LT with total BV and PV in individual variations indicated a significant negative correlation. These results indicated that 1) the relationship of peak VO2 with BV indicated a significant positive correlation, 2) the strong positive relation between shift in PV and total PV, and results in a maintenance of the circulating BV. [Jpn J Physiol 54 Suppl:S237 (2004)]
