Body fat in children and adolescents participating in organized sports: Descriptive epidemiological study of 6048 Latvian athletes.

BACKGROUND: Pressure among young athletes to meet body composition goals may lead to poor nutrition and affect growth. AIMS: To examine the proportion of body fat (%BF), measured by bioimpedance analysis, among Latvian children and adolescents participating in organized sports. METHODS: Our study had a nationally representative sample of 6048 young athletes, aged 10-17 years. Their %BF was measured using a multifrequency, 8-pole, bioelectrical impedance leg-to-hand analyzer. RESULTS: About 19.2% (CI 14.4-20.0) of boys and 15.1% (CI 14.0-16.3) of girls had a %BF value below the recommended levels. The %BF in young female athletes participating in aesthetic sports was lower than among their peers participating in other sports. Young male athletes participating in aesthetic sports had lower %BF levels at 10 and 12 years of age, compared with participants in weight-class sports; and lower levels of %BF from age 10-14 years, compared with participants in non-weight-sensitive sports. CONCLUSIONS: Almost every fifth child and adolescent participating in organized sports displayed critically low body fat levels. Body fat needs to be assessed regularly in young athletes, to prevent negative consequences on health.

Physical fitness in northern European youth: reference values from the Latvian Physical Health in Youth Study.

AIMS: Physical fitness has the potential to be used as a key health determinant in youth. The aim of this study was to establish age- and sex-stratified reference values for health-related physical fitness in Latvian school-age children and to identify notable sex differences. METHODS: Physical fitness was assessed using the EUROFIT test battery. Data were gathered from schoolchildren aged between 6 and 17 years (n = 10,464) by a medical team using standardised methods (EUROFIT battery). Fitness levels, stratified by chronological age and sex, were computed as mean ± SD. Each test was also analysed for differences between males and females in each age group. RESULTS: Boys performed better than girls in muscular endurance and strength, cardiorespiratory endurance, and speed-agility fitness tests. Girls had better flexibility than boys (p < 0.001). There was also a more pronounced improvement in physical fitness scores with age in boys compared with girls. CONCLUSIONS: Physical fitness reference values were developed for Latvian children and adolescents. These reference values will permit comparisons between students during physical education lessons and provide a baseline against which progress in physical fitness among northern European youths can be compared.