Variabilidade no crescimento somático, funcionalidade, actividade física e parâmetros de saúde : estudo em crianças e jovens rurais de Calanga, Moçambique

Leonardo Nhantumbo 6 Abstract Research studies using a biocultural approach to physical fitness (PF) in rural African population are scarce. The aims of the present study were (1) to describe the variability in somatic growth, fitness, physical activity, nutritional status (NS) and health parameters in rural children and adolescents from Mozambique; (2) to establish the interaction between chronological age, gender, body size, activity levels and socio geographic area on fitness variability; (3) to examine the relationship between fitness, physical activity, nutritional status and health parameters and age and gender and (4) to interpret somatic values and fitness levels relative to international norms of reference. The sample was composed of 845 subjects (458 boys; 387 girls) aged 6 to 17. Height and weight were measured according to the standards described by Lohman et al., (1988). Fitness was assessed using the following protocols: AAHPERD (1980) for cardiorespiratory endurance, EUROFIT (1988) for flexibility, lower limb explosive power, speed, arm muscular endurance and handgrip, and FITNESSGRAM for abdominal endurance. PA was assessed by a questionnaire conceptualized and validated for the Mozambican school-aged population (Prista et al, 2000) and by acellerometry using CSA in a subsample. Classification of NS was carried out according to criteria established by the WHO Expert Committee (WHO, 1995). Parasites and imunonohematological parameters were determined by standard laboratory protocols from blood, urine and fezes samples. For statistical analysis, ANOVA, ANCOVA, Qui Squared and Bonferroni tests were used. Height and weight values were significant lower than international norms of reference. Malnutrition prevalences for boys and girls respectively, were: stunted: 24.2% and 21.3%; wasted: 11.4% and 7.0%; stunted and wasted: 7.1% and 4.2%; overweight: 1.6% e 2.5%. There was no significant association between nutritional status and motor performance, activity levels and parasite prevalence. With the exception of lower haemoglobin and haematocrit concentrations found in girls with wasting, none of the imunohematological parameters differed significantly between nutritional groups. Fitness performance increased across age, in both sexes, and was higher in boys relative to girls. Age-sex interaction was observed for the majority of the somatic and fitness variables. Levels of PA were higher in girls than boys and in older than younger age groups. The main conclusions are: (1) a sexual dimorphism and an age effect on fitness, with an advantage for boys at older ages, but higher levels of PA for girls, partially explained by cultural factors; (2) environmental pressure on somatic growth and nutritional status, which impaired normal growth; (3) different patterns of fitness and physical activity across age and sex compared to urban and developed areas, which seems to be related to survival needs and culture; (4) higher performance relative to their peers from industrialized countries, particularly in cardiorespiratory endurance and flexibility, which is related to activity patterns and somatic characteristics.