Imbalanced nutrition of top-level swimmers

The aim of the present study was to monitor the nutritional status of 9 Greek national top-level swimmers during a competitive season of eight months. The swimmers were assessed through recording of food and supplement intake, blood sampling, and anthropometry at four landmarks: in the beginning of the season (baseline), after completing a phase of intensive and voluminous training (at 10 weeks), at a minor taper (19 weeks), and during the major taper (32 weeks). Energy and macronutrient intake did not change significantly over time, and only a few significant changes were found in micronutrient intakes. Low carbohydrate and high fat intakes (e.g., 36 and 42 % of total energy, respectively, in males), inadequate intake of some micronutrients, and improper use of supplements indicated suboptimal dietary habits. Blood hemoglobin fluctuated significantly during the season. No significant changes in parameters indicative of the iron stores (transferrin saturation and ferritin) were found, although iron intake increased by supplementation with the onset of training. Serum markers of training stress were not significantly altered. In conclusion, Greek top-level swimmers should be guided toward a balanced diet and a rational use of supplements. Monitoring of dietary intakes during a competitive season is highly recommended.