Nutritional status of U.S. elite female heptathletes during training.

This study describes the body composition, dietary nutrient intake, dietary practices, and biochemical indices of iron status of elite female American heptathletes during training. Four-day diet records and dietary practice questionnaires were obtained from 19 female heptathletes (26 +/- 3 years) during the training season. Anthropometric measurements and fasting blood samples were obtained at the lowest phase of the training cycle. These athletes had a low body fat (13.8 +/- 2.7%) and high fat-free mass to height ratios (33.0 +/- 2.0 kg/m). Average nutrient intakes were > 67% of the reference intakes for all nutrients except vitamin E. Most dietary nutrient densities were higher than NHANES III nutrient densities for women 20-29 years old. More than 50% of the athletes took vitamin supplements and monitored their hydration status. Fifteen of the 17 athletes reported a normal menstrual cycle. Markers of biochemical iron status were all within the normal range. On average, these athletes were lean with high levels of fat free mass, adequate nutrient intakes, and normal biochemical indices of iron status. However, individual data reveals considerable variability within this group.

Body composition profiles of elite American heptathletes.

This study characterized body composition profiles of elite American heptathletes and cross-validated skinfold (SKF) and bioelectrical impedance analysis (BIA) field method equations for estimation of percent body fat (%Fat) using dual energy x-ray absorptiometry (DXA) as the criterion. Weight, height, fat mass (FM), fat-free mass (FFM), bone mineral density (BMD), and %Fat were measured in 19 heptathletes using standard measurement protocols for DXA, SKFs and BIA. The ages, heights, and weights were respectively 25.5 +/- 3.5 years, 175.0 +/- 6.6 cm, 67.3 +/- 7.1 kg. DXA estimates of mean +/- SD values for body composition variables were 57.2 +/- 6.1 kg FFM, 10.1 +/- 2.6 kg FM, 114 +/- 7% BMD for age/racial reference group, and 15 +/- 3.0 %Fat. Ranges of bias values for %Fat (DXA minus SKF or BIA) were, respectively, -0.5 to 1.6% and -5.5 to -1.2%. Ranges for standard errors of estimate and total errors were, respectively, SKF 2.4-2.5%, 2.4 - 2.8% and BIA 3.0%, 5.0-6.5%. Regression analyses of the field methods on DXA were significant (p < .05) for all SKF equations but not BIA equations. This study demonstrates that elite American heptathletes are lean, have high levels of BMD, and that SKF equations provide more accurate estimates of %Fat relative to DXA than estimates from BIA equations.