Abstract

Although marked reticulocytosis occurred in both groups, it was significant more pronounced in the firm-sole group. The positive correlation between percent reticulocytes and Peak g suggests that shoe rearfoot cushioning is one determinant of the erythropoietic response to increased training mileage in distance runners. We studied erythropoietic activity in relation to the rearfoot cushioning of shoes worn by 14 male runners before, during, and the morning after a 17-day period of increased training mileage. The percentage of reticulocytes in the red blood cell count served as the marker for erythropoietic activity. Each runner was assigned to either a firm-sole group (7) or a soft-sole group (7) according to the heel impact attenuation character (Peak g) of his shoes. Peak g was 18 greater in the firm-sole group. Otherwise, the groups were similar in physical characteristics, training mileage, and running ability. All subjects ran a total of 430 km, a distance that averaged 79 higher than their regular training distance for a 17-day period. Verf.-Referat