Mukherjee, Swarup

Body composition is an important aspect of soccer fitness. There is a dearth of longitudinal data on the intraseasonal variation in the body composition parameters of youth professional soccer players especially of Asian origin. This study assessed the body composition profile of the Asian youth professional soccer players (n=20; Mean ± SD, age 17.5 ± 0.3 years, stature 1.73 ± 0.04 m, body mass 67.2 ± 7.5 kg) through the entire season. Body mass, percentage body fat (% BF), lean body mass (LBM) and bone mineral density (BMD) of outfield youth professional soccer players was determined using dual-energy x-ray absorptiometry (DXA) during the pre-season, early in-season and end mid-season respectively. Results showed that the Asian youth professional soccer players had similar anthropometric characteristics compared to Asian adult elite players but were shorter and lighter than European youth players. There was a significant decrease (p < 0.05) in the % BF and a significant increase (p < 0.05) in LBM during the pre-season period. However, negative adaptations during the competition phase indicated that training and competition load was insufficient to improve or maintain the adaptations in the % BF and LBM. The whole body BMD significantly increased through the soccer season. Area-specific BMD of the pelvis and the lower limbs showed positive osteogenic adaptations during the soccer season. Our results showed that the body composition parameters of Asian youth professional soccer players change through the soccer season. Such data can expand the bases of comparison between different soccer playing populations and add to the prospects of research on soccer performance. Further studies on the effect of body composition parameters on different aspects of soccer performance are desirable.

Aim Population-specific waist circumference (WC) percentiles are crucial for screening children at higher obesity-related metabolic risk. This study aimed to develop age- and gender-specific WC percentile curves for Singaporean children and adolescents. Methods 3029 participants (boys, 1506; girls, 1523) from different population strata of Singapore were recruited. Stature, weight and WC were measured and BMI calculated. Smoothed WC percentile curves and cut-offs for the 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th, 97th were constructed using the Cole's LMS method. Results WC and BMI increased with age in both sexes and boys had higher WC than girls at every age. Comparison of 50th and 90th percentiles with other populations showed distinct difference in WC curve patterns and values of Singaporean children. Conclusions We present the first working WC percentile curves and age- and gender-specific cut-offs of Singaporean children and adolescents. These cut-offs and curves can serve as valuable reference for screening and identify children at a higher metabolic risk, for international comparisons and to better understand secular trends in paediatric obesity.