Bioimpedance standards are well established for the normal healthy population and in clinical settings, but they are not available for many sports categories. The aim of this study was to develop reference values for male and female athletes using classic bioimpedance vector analysis (BIVA). In this study, 1556 athletes engaged in different sports were evaluated during their off-season period. A tetrapolar bioelectrical impedance analyzer was used to determine measurements of resistance (R) and reactance (Xc). The classic BIVA procedure, which corrects bioelectrical values for body height, was applied, and fat-free mass, fat mass, and total body water were estimated. In order to verify the need for specific references, classic bioelectrical values were compared to the reference values for the general male and female populations. Additionally, athletes were divided into three groups: endurance, velocity/power, and team sports. In comparison with the general healthy male and female populations, the mean vectors of the athletes showed a shift to the left on the R–Xc graph. Considering the same set of modalities, BIVA confidence graphs showed that male and female endurance athletes presented lower body fluids, fat mass, and fat-free mass than other sets of modalities. This study provides BIVA reference values for an athletic population that can be used as a standard for assessing body composition in male and female athletes.

The aim of this retrospective study was to determine the long-term effect of exercise on bone mineral density (BMD), bone mineral content (BMC) and body composition (BC) in post-menopausal women who were elite athletes during their youth compared with sedentary controls. /Methods:It is a retrospective study and carried out in an outpatient clinic. A total of 48 post-menopausal women (54–73 years of age) were enrolled. Ex-elite athletes with long-term (>20 years) histories of significant training and performance were divided into two groups: weight-bearing sports (runners, n=12) and non-weight-bearing sports (swimmers, n=12). The athletes were age matched with sedentary controls (n=24). BMD, BMC and BC were measured using dual-energy X-ray absorptiometry. Healthcare and sport activity histories were evaluated using a questionnaire. No significant differences were found with regard to body weight, height, body mass index and hours of activity between the two groups of athletes. There were no significant differences in activity levels between athletes and controls at the time of this study. BMD and BMC were not significantly different between athletes; they were significantly higher in athletes than in controls (P<0.001). Although the ex-athletes did not significantly differ in BC, left and right lean arm mass and arm BMD were significantly higher in swimmers than in runners (P<0.0001). The high level of physical activity observed in female athletes is associated with improved muscle mass, BMD and BMC, and physical activity during youth seems to have a beneficial effect on bone mass and helps to prevent bone loss due to aging.

The present study aimed to develop reference values for bioelectrical phase angle in male and female athletes from different sports. Overall, 2224 subjects participated in this study [1658 males (age 26.2 ± 8.9 y) and 566 females (age 26.9 ± 6.6 y)]. Participants were categorized by their sport discipline and sorted into three different sport modalities: endurance, velocity/power, and team sports. Phase angle was directly measured using a foot-to-hand bioimpedance technology at a 50 kHz frequency during the in-season period. Reference percentiles (5th, 15th, 50th, 85th, and 95th) were calculated and stratified by sex, sport discipline and modality using an empirical Bayesian analysis. This method allows for the sharing of information between different groups, creating reference percentiles, even for sports disciplines with few observations. Phase angle differed (men: p < 0.001; women: p = 0.003) among the three sport modalities, where endurance athletes showed a lower value than the other groups (men: vs. velocity/power: p = 0.010, 95% CI = −0.43 to −0.04; vs. team sports: p < 0.001, 95% CI = −0.48 to −0.02; women: vs. velocity/power: p = 0.002, 95% CI = −0.59 to −0.10; vs. team sports: p = 0.015, 95% CI = −0.52 to −0.04). Male athletes showed a higher phase angle than female athletes within each sport modality (endurance: p < 0.01, 95% CI = 0.63 to 1.14; velocity/power: p < 0.01, 95% CI = 0.68 to 1.07; team sports: p < 0.01, 95% CI = 0.98 to 1.23). We derived phase angle reference percentiles for endurance, velocity/power, and team sports athletes. Additionally, we calculated sex-specific references for a total of 22 and 19 sport disciplines for male and female athletes, respectively. This study provides sex- and sport-specific percentiles for phase angle that can track body composition and performance-related parameters in athletes.