Increase In Muscularity Indicators Over A 10-years Period.

Muscularity has an impact on health and quality of life. The arm muscle circumference (AMC) is one of the best predictors of nutritional status, with malnutrition (depletion of lean mass) being related to a high risk of premature mortality. PURPOSE: Compare muscularity over a 10-year period in schoolchildren of both sexes. METHODS: The study is part of the Ilhabela Mixed Longitudinal Growth, Development and Physical Fitness Project. A convenience sample was made up of 454 students, 256 boys and 198 girls, divided into 2 periods: 2008-2009 and 2018-2019. The mean age for girls in 2008-2009 and 2018-2019 was 10 years old and the mean age for boys in 2008-2009 was 10.5 years old and in 2018-2019 was 11 years old. The following variables were analyzed: weight (kg), height (cm), BMI (kg/m2), mean of 7 skinfolds (biceps, triceps, subscapular, suprailiac, middle axillary, abdominal, and medial calf), and the mean of 3 skinfolds (triceps, subscapular, suprailiac), arm circumference, triceps skinfold, calf circumference (CC), and arm circumference (cm). Statistical analysis: Data normality was determined using the Kolmogorov-Smirnov test, followed by the U-Mann Whitney test to compare groups, using SPSS 25.0 software, with a significance level of p < .01. RESULTS: Over a 10 years period, there was a significant increase in all variables analyzed. There was an increase in muscle mass indicators of the upper limbs (AMC) and lower limbs (calf circumference) in both sexes despite the increase in body adiposity. CONCLUSIONS: We concluded that there was an increase in muscularity indicators over a period of 10 years in schoolchildren. Table 1. - Comparison of anthropometric variables, body composition and muscularity indicators Variable - Boys (n = 256) 2008/09 (N = 155) 2018/19 (N = 101) Δ% p Mean Mean BMI (kg/m2) 17 18,1 5,8 <0,001 X7DC (mm) 7,4 9,7 31,1 <0,001 X3DC (mm) 7,5 9,5 26,7 0,001 AMC (cm) 16,1 17,3 7,4 <0,001 CC (cm) 27,3 28,3 3.6 <0,001 Variable - Girls (n = 198) 2008/09 (N = 108) 2018/19 (N = 90) Δ% P Mean Mean BMI (kg/m2) 16,9 19,1 13,1 <0,001 X7DC (mm) 9,4 11,7 24,5 0,004 X3DC (mm) 9,2 11,5 25 0,001 AMC (cm) 16,2 18 11,1 <0,001 CC (cm) 28,4 30,2 6,3 <0,001