Effects of exercise on rheological and microcirculatory parameters

The physiological changes occurring during exercise and its possible consequences have been receiving considerable attention lately. In this paper, we studied the changes in hemorheological and microcirculatory parameters, before and after the exercise, in the subjects undergoing mild exercise (n = 20). A cycle ergometer adjusted at 2.5 kilopounds was used for 15 minutes. The whole blood viscosity showed a significant increase after exercise at all shear rates (0.512-51.2/s) except at the high shear rate (94.5/s). However, the significant level was more (P < 0.005) at low shear rates (0.512-4.39/s). A significant elevation in plasma viscosity was observed after the exercise (P < 0.0008). Red cell rigidity showed a significant increase after the exercise (P < 0.001) while red cell aggregation and hematocrit failed to show any significant change. Microcirculatory studies showed a significant increase in the basal perfusion level after exercise (P < 0.0002) when compared to the resting state value. There was a significant decrease in reactive hyperaemia perfusion index after exercise (P < 0.0007). Hence, it is evident from this study that short-term exercise significantly alters hemorheological and microcirculatory parameters.