Effects of iron intake through food or supplement on iron status and performance of healthy adolescent swimmers during a training season.

摘要

Maintenance of a normal iron status is important for swimming performance during training and competition. The purpose of this study was to investigate whether 1) the iron status of healthy adolescent swimmers changes during a training season of six months, and 2) increasing daily iron intake affects iron status or performance. Forty-two (21 male and 21 female) swimmers, aged 12 - 17, without anemia or iron deficiency were divided into three equal groups. Group A received an iron supplement of 47 mg per day, group B followed a dietary plan rich in iron (providing, on average, 26 mg per day), and group C had a regular diet. Blood samples were taken before the beginning of the study and at the end of each of three training phases (moderate intensity training, high intensity training, and tapering) for the determination of hematological and iron status parameters. To evaluate performance, swimming tests at different distances were conducted along with blood sampling. The results showed significant fluctuations of iron status during the training season, including an increase in erythrocyte parameters during moderate intensity training. No significant differences in iron status or performance were found among the three groups. In conclusion, iron status and performance of healthy adolescent swimmers were affected by training irrespective of iron intake ranging from one to over five times the RDA over a period of six months.