Post-exercise anaemia as a result of exercise overloading of the organism.

The aim of the present study was to determine the relation between the exercise load used in training and the changes in the basic parameters of the erythrocytic system. The experiments were carried out on 33 Wistar rats (females and males). The animals were forced to run at a velocity of 1.47 km/h inside an electrically-driven rotating drum. The experiments were performed for 35 days. In the 1st - (females) and 2nd - (males) group the exercise period was prolonged by 1 min per day on successive days, and by 2 min per day in the 3rd - (females) and 4th - (males) group. Prior to and after the training period the haemoglobin concentration, haematocrit, erythrocyte and reticulocyte counts were determined in the venous blood. Reticulocytes were divided into four age groups and the percentage each particular age group was calculated. All the trained groups manifested a decrease in haemoglobin concentration, hematocrit values and erythrocyte count and a concomitant elevation of the reticulocyte count with a shift towards youngest forms was found. Rats of the 3rd and 4th groups developed post-exercise anaemia.