Objectively measured physical activity and body composition indices in Brazilian adolescents

Abstract

The aim of the study was to explore the association between objectively measured physical activity and body composition indices in 13-year old adolescents living in country undergoing rapid nutritional transition. A population-based cross-sectional study nested within the 1993 Pelotas (Brazil) Birth Cohort was undertaken. A total of 457 boys and girls (80.5% of the target sample, 52.1% boys) participated in the study. Physical activity was measured by the Actigraph accelerometer for 5 consecutive days and expressed as total physical activity (i.e. average intensity, counts per minute) and time (min per day) spent at moderate and vigorous intensity activity. The outcomes investigated were sum of triceps and subscapular skinfolds, waist circumference, waist-to-hip ratio and waist-to-thigh ratio. After adjustment for sex, socioeconomic status, age, Tanner stage of sexual maturation, diet pattern, height, and birth weight, time (min/day) spent at vigorous intensity activity was inversely associated with waist circumference and sum of skinfolds. A one minute/day increase in vigorous intensity physical activity was associated, on average, with a reduction of 0.15cm in waist circumference (p=0.007) and 0.20mm in sum of skinfold thicknesses (p=0.02). These associations were stronger in boys than in girls. Total activity and time spent in moderate intensity physical activities were not associated with any of the outcomes in the adjusted analyses. Vigorous physical activity appears to have the strongest association with body composition. Preventive efforts aimed to decrease the obesity in adolescents may be more successful if they focus on vigorous intensity, instead of moderate intensity physical activities. KeywordsBrazil; Accelerometry; Adiposity; Body fat; Motor activity; Activity monitors. Resumo

The prevalence of global physical activity among young people: a systematic review for the Report Card Brazil 2018

“…Regarding objective measurements of PA, the population-based study that used accelerometers 61 was conducted in South Brazil with 457 adolescents who were 12-14 years old. This study found overall prevalence of physically active of 61.3% 61 . A school-based study with 1139 6-8-year-old students from Northeastern Brazil the used pedometer-measured physical activity found an overall prevalence of 35.7% physically active individuals 23 (Table 2).…”

“…Almost all studies (n = 59) were school-based surveys 8, 9 , 18-27, 10, 28, 29, 31-37, 39, 11, 40- . Three 61,82,102 were population-based studies. In terms of age, three (4.9%) studies included 6-10 year-old children 29,85,86 , 52 (85.2%) studies included 10-19 year-old adolescents 8, 9, 21, 22, 24-31, 10, 32-34, 36-42, 11, 43, 45-47, 49-54, 14, 55-64, 16, 65-74, 17, 75, 76, 78-84, 87, 18, 88, 90-94, 96-99, 19, 101, 102, 20 , and six (9.8%) studies included individuals from both age groups 12,13,23,35,77,89,95 .…”

“…The most used instruments were: the International Physical Activity Questionnaire (IPAQ , 12 studies) 22,36,88,99,102,55,59,60,64,65,76,77,82 , the Global School-Health Survey instrument (GSHS, 8 studies) 11,21,[66][67][68]79,84,96,24,25,29,32,37,41,42,56 , and the Physical Activity Questionnaire for Older Children and Adolescents (PAQ-C and PAQ-A, 10 studies) 12,13,97,101,[16][17][18]31,39,58,72,92 . Finally, one study used pedometermeasured physical activity 23 and one study used accelerometer-measured physical activity 61 (Table 1).…”

“…Inversely, this systematic review included only two studies with objectively-measured physical activity 23,61 . In Brazil, the high cost of objective measures of physical activity can still be a barrier to their use in comprehensive survey studies.…”

The Relationship between Body Composition and Physical Fitness Parameters in Children

“…There is a strong relationship between physical activity and body composition (Reicherte et al, 2012). The general aim of studies on body height, structure and composition is to determine and develop physical fitness individually (Artioli et al, 2008).…”