Adverse effects of alcohol ingestion post exercise on blood rheological variables during recovery

The present study examined the influence of ingesting a moderate dose of alcohol on the main determinants of blood rheology namely: plasma viscosity, plasma fibrinogen concentration, plasma total protein concentration, and haematocrit. Eleven moderately active young men were studied immediately after a standardised cycle ergometer test and during the 24 h period of recovery. Alcohol (0.7 g/kg body mass) was given 1 h after exercise on one test occasion, while an equal volume of alcohol-free solution was administered on the other. Venous blood samples were obtained at baseline, post exercise, and at 1, 5, and 22 h post alcohol ingestion. A significant reduction in plasma volume was observed immediately after exercise, but this decrease was restored 1-h post drink ingestion. Blood alcohol level increased significantly 1 h after the ingestion of alcohol, but decreased and returned to the resting baseline level at 5 h during recovery. Exercise induced significant changes (P<0.05) in blood rheology as manifested by a significant increase (P<0.05) in plasma viscosity and plasma fibrinogen. Parallel increase (P<0.05) in haematocrit and total protein was also observed after exercise. The increase in these rheological variables immediately after exercise was mainly due to exercise-induced plasma volume loss. During recovery, while the increase in haematocrit post-exercise returned to the baseline level in both control and alcohol trials, plasma viscosity and plasma fibrinogen remained significantly high during recovery in the alcohol trial compared with control condition. It is concluded that exercise induces significant changes in the main determinants of blood rheology and the consumption of alcohol after physical exercise delays the normal return of plasma viscosity, plasma fibrinogen to the resting baseline levels during recovery. Although the mechanism responsible for these findings is not, as yet known, it might be linked with alcohol induce dehydration.