Body composition and body weight may impact health and performance. While the most used classification of body composition in non athletes is the Body Mass Index (BMI), no studies have assessed the relationship between BMI and body fat percent (BF%) in elite female athletes and compared with normal-active controls. Therefore, the aims of this study were to assess the relationship between BMI and BF% in elite female athletes representing several sports, and to compare with non-athlete controls Methods: This two-phase study included: 1) a questionnaire regarding training patterns, menstrual-, dietary-, and weight history, nutritional factors, oral contraceptive use, pregnancy, stress fractures, and disordered eating behaviours, and 2) measurement of body composition with dual-energy X-ray absorptiometry using a full body scan on a LUNAR-Prodigy. In part I, all female athletes representing the national teams of Norway at the junior or senior level, aged 13-39 years (n=938) and a same-age random sample control group (n=900) were invited.. The questionnaire was completed by 88% of the athletes and 70% of the controls. Based on these initial data, a random sample of athletes (n=300) and controls (n=300) were selected and invited to participate in part II. A total of 186 athletes (62%) and 145 controls (48%) participated in part II. Overfatness was defined as a BF% >/= 33% (Ode et al. 2007). Results: The athletes had a significantly lower BMI (21.7 ± 2.4 kg/m2) and BF% (24.2 ± 7.2%) compared with the controls (24.0 ±4.2 kg/m2 and 35.5 ±7.1%) (p<0.001). The correlation between BMI and BF% was 0.671 (p<0.01) for athletes and 0.813 (p<0.01) for controls. Of those athletes with normal BMI values (n=150), 6,7% were classified as overfat. Seven athletes were classified as overweight based on their BMI values, but not overfat. For the controls with normal BMI values (n=96), 50,0% were classified as overfat. A total of 63,4% of the controls had a BF >/= ;33%, a level several times higher than that of the athlete group (11.3%) (p<0.001). Discussion: As expected, the athletes had lower BMI and BF% than the controls. The correlation between BMI values and BF% is acceptable for both athletes and controls. However, of those athletes and controls with normal BMI values, 7% and 50% of the sample respectively, had a BF >/= ;33%, and were classified as overfat. On the contrary, 4% of the athletes were classified as overweight without being overfat. Thus,BF% should be preferentially used over BMI as a tool for validly classifying body composition in young female athletes and in the general female population. We recommend future studies to develop a classification of BF% values for health status and ranges of BF%. Furthermore, recommended levels of BF% for different sport groups are needed.
© Copyright 2009 14th annual Congress of the European College of Sport Science, Oslo/Norway, June 24-27, 2009, Book of Abstracts. Julkaistu Tekijä The Norwegian School of Sport Sciences. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator