[Residual effect of muscle strength exercise in secondary prevention of children obesity]

The high prevalence of the obesity in Chilean students (23,1%), necessitates the application of interventions that incorporate muscle strength exercise, as this shows great efficacy in obese children.

To evaluate the residual effect of muscle strength exercise on body fat, metabolic syndrome and physical fitness in obese schoolchildren.

The sample included 111 obese schoolchildren, between 8 and 13 years, of 3 schools in the city of Santiago. Early intervention (n = 60) participated in parallel intervention that included muscle strength exercise, nutrition education and psychological support for 3 months. The late intervention (n = 51) incorporated the first 3 months, only the educational intervention and psychological support, and exercise was added between 3 and 6 months. At 9 months post intervention, we evaluated the residual effect of exercise. Body fat was determined by anthropometric equations. The metabolic syndrome was diagnosed by the criteria of Cook. Physical fitness was assessed by the distance walked in six minutes test.

The body fat percentage decreased at the end of the intervention and post intervention increased with the exception of the men of early intervention. The distance traveled increased at the end of the intervention but declined in the post intervention. Metabolic syndrome, decreased at the end of the intervention increased post intervention (p < 0,05).

The sustainability of the exercise is essential to maintain the changes, which is checked to determine the residual effect of exercise on body fat, metabolic syndrome and physical condition.