Date of Award
Master of Science
Food Science and Human Nutrition
The purpose of this study was to determine the effect of training on body composition, dietary intake, and iron status of female collegiate swimmers and whether nutrition attitudes are correlated to dietary choices. Measurements were obtained on 24 eumenorrheic Iowa State University female collegiate swimmers (swimmers, n=18; divers, n=6) at preseason, before competition, and after 16-weeks of training. Training consisted of 3 days/week on dry land (resistance, strength, flexibility; 1.5 hours/day) and 6 days/week in-water (7,000-11,000 yards/day; nine, 2 hour sessions/week). Body composition was assessed using dual-energy x-ray absorptiometry (DXA). Changes were documented in body composition, regional fat and lean tissue distribution, dietary intake, and iron status using paired t-tests. We also examined the relationship between dietary changes and nutrition attitudes using correlation analyses. There were decreases in BMI (P=0.05), waist circumference (P[Less than or equal to symbol]0.0001), hip circumference (P[Less than or equal to symbol]0.0001), whole body fat weight (P=0.0002), and percentage body fat (P[Less than or equal to symbol]0.0001); lean weight (P=0.028) increased. We found no significant change in regional lean distribution, but documented a decrease in fat at the waist (P=0.0002), hip (P=0.0002), and thigh (P=0.002). Energy intake at preseason averaged 2403±864 kcal-day−1 with macronutrient composition of 62% carbohydrate, 13% protein, and 24% fat; no changes were noted from preseason to late season. Dietary fiber (P=0.036), iron (P=0.015), vitamin C (P=0.029), vitamin B6 (P=0.032), and fruit exchanges (P=0.003) increased. A higher nutrition attitude score was correlated with a higher intake of calcium (P=0.02), milk exchanges (P=0.04), and fruit exchanges (P=0.019). We documented an increase in hemoglobin (Hb) (P=0.046) and hematocrit (Hct) (P=0.014) and a decrease in serum transferrin receptor (P[Less than or equal to symbol]0.0001). In summary, after 16-weeks of training, female collegiate swimmers decreased overall body fat and increased lean weight. Dietary quality improved with an increase in dietary fiber, iron, vitamin C, vitamin B6, and fruit exchanges, as well as a decrease in fat exchanges. A more positive nutrition attitude score was correlated with higher intakes of calcium, milk, and fruit. Iron status improved with an increase in Hb, Hct, and a decrease in serum TfR. Additional studies to evaluate body composition and iron status in relation to dietary intake in female collegiate swimmers are warranted.
Heidi Lyn Petersen
Petersen, Heidi Lyn, "Body composition, dietary intake, and iron status of female collegiate swimmers" (2002). Retrospective Theses and Dissertations. 20200.