Low values of blood viscosity and erythrocyte aggregation are associated with lower increases in blood lactate during submaximal exercise

Article type: Research Article

Authors: Brun, J.F. | Supparo, I. | Fons, C. | El Bouhmadi, A. | Orsetti, A.

Affiliations: Service d'Exploration Physiologique des Hormones et des Metabolismes, CHU de Montpellier F-34059 Montpellier, France

Abstract: Trained sportsmen have low values of blood viscosity (ηb). In this study we tested the functional consequences of this reduction of ηb in 34 sportsmen submitted to a 25 min progressively increasing submaximal work load. A low resting ηb (measured at high shear rate with the MT90 viscometer) was associated to a lower increase in blood lactate during exercise (correlation of ηb with: maximal lactate value: r=0.357 p < 0.05; area under the curve: r=0.490 p < 0.01). Subjects with ηb > 2.4 mPa.s (with this method) had higher lactate increase (p < 0.01) and a deeper decrease in blood bicarbonate (p < 0.001). RBC rigidity (‘Tk’ index) is increased proportionaly to lactate when lactate increases above 4 mmol.l−1. Another group of 21 professional footballers was studied during a maximal triangular work load until VO2 max. In this group there was a correlation between maximal lactate response during the test and RBC aggregation (r=0.705 p < 0.005). These results suggest that low whole blood viscosity at rest either (a) prevents from excessive lactate increase in this kind of exercise protocol; (b) or is a marker of trained persons characterized by metabolic/circulatory adaptations protecting against exercise-induced hyperlactatemia. In these experimental conditions lower RBC aggregation (within the normal range) seems to be also associated with fitness and lower lactate increase.

Keywords: Blood viscosity, hematocrit, exercise, football, hemorheology, erythrocyte deformability, erythrocyte aggregation, blood lactate

DOI: 10.3233/CH-1994-14114

Journal: Clinical Hemorheology and Microcirculation, vol. 14, no. 1, pp. 105-116, 1994