Efeitos da prática da natação sobre fatores de risco cardiovascular e aptidão física em crianças e adolescentes eutróficos e com excesso de peso

Abstract

This study evaluated the effect of swimming practice on cardiovascular risk factors and physical fitness in obese and non obese school age children and adolescents. A group of 49 children aged 8-15 years (26 girls) underwent anthropometric, physical activity, cardiorespiratory fitness, autonomic modulation, and laboratory (energy and inflammatory metabolism) assessments before and after 3, 6 and 12 months of swimming intervention. Abdominal fat distribution and carotid intima media thickness were evaluated by ultrasound. Endothelial function was assessed through peripheral arterial tonometry and venous occlusion plethysmography. Swimming consisted of 50-min sessions performed twice a week, including aquatic adaptation, fluctuation, breathing and displacement exercises, in addition to techniques of the four swimming styles. Outpatient follow-up consisted of four clinical consultations and nutritional counseling. Participants were classified according to intervention and z- score of body mass index (Z-BMI): eutrophic swimming (EUS: n = 14); overweight swimming (OVS: n = 20); and sedentary overweight (SEOV: n = 15), in addition to the following subgroups: obese swimming (OBS: n = 10); sedentary obese (SEOB: n = 11). After 6 months, significant reductions (p <0.05) occurred in OVS for waist to height ratio (~ 5%); OBS for Z-BMI (~5%), systolic (~11%) and diastolic (~10%) blood pressure; and in EUS for systolic (~6%). Significant increases (p <0.05) occurred in OVS for the levels of physical activity (~40%), distance covered in the Yoyo test (~28%), RR intervals (~7%) and vagal tone (~19%); and in OBS for the reactive hyperemia index (~33%). After the intervention, OVS exhibited similar insulinemia to EUS, contrarily to the greater values at baseline. The HDL-colesterol was higher among overweight group who practiced swimming vs. sedentary counterparts (p = 0.01). After 12 months of swimming, OBS showed significant reductions (p <0.05) in leptin (~7%) and TNFα (~15%). The amount of intra-abdominal fat in OVS approached the profile of eutrophic individuals, while baseline differences in the thickness of the left carotid (greater in OVS vs. SEOV) disappeared after the intervention. In conclusion, regular practice of swimming seems to be beneficial to cardiovascular health, and effective to improve body composition, cardiorespiratory fitness, autonomic modulation, blood pressure, lipid and inflammatory profile in overweight and obese children and adolescents.