Extensive training processes are very often followed by changes in blood composition. There is evidence of the high correlation between the training rate and intensity of exercise and the athlete's hipochromy. In athletes we found a characteristic non-anemic iron deficit. Our goal was to monitor the hematological parameters in athletes with hipochromy and to examine the period of correction using iron supplementation. 20 male and 20 female athletes ages 18-22 years took part in the study. Blood samples were collected and the total number of erythrocytes, hemoglobin, serum iron and the staining index were calculated. All athletes received Earthrise Spirulina tablets, containing 1.5 mg Fe2+, 3 times a day for 2 months. Monitoring was done for 3 months. Significant changes were found in the female group for hemoglobin level, as well as increase of the serum iron and staining index. Distinct rise of the serum iron was observed in both male and female athletes. The clinical symptoms such as exhaustion, muscle fatigue and somnolence disappeared after the correction of the iron deficit. Addition of spirulina improves the prevention of non-anemic iron deficiency in athletes expecially females. Improvement of the iron reserves is a simple dietary modification that can optimize athletes health and physical capacity.