Effect of increased training volume on nutrient intake of male collegiate swimmers

To assess the effect of a period of increasing training on dietary quantity and quality, a men's collegiate swim team (n = 24) was divided into two groups of equal skill at the start of a 25-week season of training and competition. After a 4-week conditioning period, the "Long" group underwent a 6-week period during which they swam up to 44,000 m.wk-1, while the "Short" group maintained their swimming at 22,000 m.wk-1. For the remainder of the season, the two groups swam together, performing the same volume and intensity of training. Two-day food intake records were obtained during the early season, during the period of increased training, and during the late season. Swimmers' diets during the early season averaged 15.3 MJ, with 55% from carbohydrate (500 g), and exceeded RDAs for all nutrients assessed. During the increased training period, energy and carbohydrate intakes of the Long group increased significantly (p less than 0.05) to 17.7 MJ and 600 g respectively, but the percentage of energy derived from carbohydrate, protein and fat was stable. Intakes of the Short group did not change over the season. Energy intake did not fully compensate for expenditure, as both groups maintained weight but lost subcutaneous fat. An increase in training volume appears to result in an increased consumption of the athletes' usual diets.