Haemorheological changes associated with prolonged walking on different diets

Abstract

Haemorheologtcal and red cell age-related indices were measured in male subjects before and after two bouts of prolonged walking (148km) each lasting 4 days. During the walk subjects consumed isoenergetic diets which were either low (2 ± 0%, mean ± SD) or high (85 ± 1%) in carbohydrate (CHO). There was a significant reduction in the uncorrected whole blood viscosity only on the high CHO diet, primarily due to a greater extent of the haemodilution which was evident on both diets. In addition, plasma viscosity was significantly elevated on the low CHO diet but unchanged on the high CHO diet, these dietary differences being associated with alterations in serum protein concentration. Red cell deformability was reduced only on the low CHO diet and there was also an increase in median cell density in Percoll gradients indicating general aging of the cell population. Increases in reticulocyte number and red cell creatine recorded only on the low carbohydrate diet (high protein and fat) are consistent with increased erythropoietic activity.