Impacto da atividade física e esportes sobre o crescimento e puberdade de crianças e adolescentes Linear growth and puberty in children and adolescents: effects of physical activity and sports

OBJETIVO: Apresentar revisão atualizada e crítica sobre o impacto do esporte e da atividade física no crescimento, desenvolvimento puberal e mineralização óssea de crianças e adolescentes. FONTES DE DADOS: Pesquisa bibliográfica nos bancos de dados Medline e Lilacs (1987-2007), selecionando os artigos escritos em inglês, português ou espanhol, a partir dos descritores "esportes" e "exercícios", em combinação com "crescimento", "puberdade" e "mineralização óssea". Foram examinados 252 artigos e 48 deles selecionados. SÍNTESE DOS DADOS: Diferentes modalidades esportivas não aumentam ou diminuem a estatura. Ocorre um viés de seleção, no qual fatores constitucionais determinam a seleção de biótipos privilegiados para determinados esportes. O exercício físico leve a moderado estimula o crescimento e deve ser incentivado. A atividade física extenuante, principalmente quando associada à restrição dietética, afeta o crescimento, o desenvolvimento puberal, a função reprodutiva e a mineralização óssea. A musculação praticada por jovens pré-púberes pode ser prejudicial, se não for realizada sob supervisão, já que há um potencial risco de lesão na cartilagem de crescimento. Entretanto, quando bem supervisionada, pode levar a um aumento de força e resistência muscular. CONCLUSÕES: Os efeitos deletérios dos esportes sobre o crescimento e desenvolvimento só foram observados em atletas de elite submetidos a treinamento intensivo e restrição alimentar. Alterações hormonais e de citocinas inflamatórias são parte da fisiopatologia desse processo. É necessário que estudos longitudinais avaliem as repercussões da atividade física recreacional sobre a estatura final.<br>OBJECTIVE: To present an up-to-date critical review about the impact of sports and physical activity on growth, pubertal development and bone mineralization of children and adolescents. DATA SOURCE: Bibliographic search of Medline and Lilacs databases (1987-2007) with selection of studies written in English, Portuguese or Spanish, with the descriptors "sports" and "exercise" in combination with "growth", "puberty" and "bone mineralization". A total of 252 articles were retrieved and 48 of them were selected. DATA SYNTHESIS: Light to moderate physical activity has a beneficial effect on growth and bone development, while intense physical training, specially if associated to dietary restrictions, may attenuate linear growth, pubertal development, reproductive function and bone mineralization. Different sports do not have specific effects on final height. There is a selection bias in which constitutional factors contribute to select favored biotypes to specific sports. Weight-training by pre-pubertal children may be harmful, if not supervised, due to the potential risk of injure to the growth plates; however, if performed under strict supervision, may provide muscle strength and resistance. CONCLUSIONS: Deleterious effects of sports in growth and development of children and adolescents were only observed in elite athletes submitted to intensive training and dietetic restriction. Longitudinal studies are neded to evaluate the effects of recreational physical activity upon linear growth

Fitness, Diet and Coronary Risk Factors in a Sample of Southeastern U.S. Children.

The purpose of this study was to evaluate the relationship between physical fitness variables and nutrient intake to coronary risk factors (CRF) in a sample of children living in the Southeastern U.S. A total of 22 sixth-grade children of whom 10 were boys (mean age = 11.83 ± 0.3) and 12 were girls (mean age 11.7 ± 0.3) volunteered for this study. Results indicated that boys in comparison to girls weighed more (54.0 ± 10.8 kg versus 42.1 ± 8.0 kg; p<0.05), had a higher body mass index (BMI) (23.6 ± 2.7versus 20.2 ± 3.3; p<0.05), a higher lean body mass (37.8 ± 6.0 kg versus 30.7 ± 3.8 kg; p<0.01), and a higher systolic blood pressure (115.7 ± 11.1 versus 106.4 ± 8.1; p<.0001). There were, however, no significant gender differences in serum lipoproteins or nutrient intake. Stepwise multiple regression analyses indicated that physical fitness variables which included VO2max, one-mile run for time, grip strength, and leg strength could significantly predict resting diastolic blood pressure (DBP) (F=3.06; p<0.05) and percent body fat (F=4.98; p<0.01) in children. Analysis of food intake revealed that total and saturated fat, and carbohydrate intake could predict serum triglycerides (TG) (F=5.18; p=0.01) while total kilocalorie, fat, and carbohydrate intake could significantly predict percent body fat (F=3.42; p<0.03). These findings may be clinically relevant since both serum triglyceride levels and percent body fat were well above the 50th percentile according to U.S. norms. In summary, the present study showed that measurements of muscular strength in addition to aerobic fitness are associated with DBP and percent body fat in children. Furthermore, it is recommended that nutrient intake be used when evaluating CRF in children due to its ability to predict TG and percent body fat