Effect of physical training on hematological parameters in young swimmers

PURPOSE: To evaluate the effects of a regular training programme on some haematological values in a group of young swimmers. MATERIAL AND METHODS: The study group is composed of 32 infantile swimmers (18 boys and 14 girls) and the control group of 12 boys and 11 girls of similar ages, performing no sports. Blood samples were taken at the beginning of training and four months later. Automated blood cell counts were performed in duplicate, along with assessment of the serum levels of iron, ferritin, transferrin and haptoglobin. The statistical study was made by comparison of means (Student's t, Wilcoxon and Mann-Whitney's U tests). RESULTS: Significant descent of haemoglobin rates (p < 0.05) was found in the swimmers, whereas serum iron was also significantly decreased (p < 0.01). Transferrin and haptoglobin were increased in both sexes (p < 0.01) in the swimmers, while ferritin was increased only in the female swimmers. With regard to the control groups, the boys showed significantly higher levels of ferritin both at the beginning and the end of the test, whereas the girls had lower only at the beginning (p < 0.01). CONCLUSIONS: After a 4-month physical training programme the tissular iron deposits are increased in a population of infantile swimmers, such increase being significant only in females.