[Body composition, physical fitness and physical training in schoolchildren from a public school].

Objective: To describe the body composition, physical fitness and biochemical risk markers before and after implementation of a physical exercise program in adolescents aged 10 to 17 years of a public school.

Methodology: Study with an experimental approach, the sample consisted of 276 schoolchildren, (141) intervention group and (135) control group. Informed consent and assent were completed, anthropometric measurements were taken, the Fitnessgram battery tests were carried out, and a physical exercise program was implemented.

Results: Post implementation of the physical exercise program, weight gain and waist circumference were reported in girls. Schoolchildren from 10 to 13 showed a decrease in cholesterol and triglycerides. Men performed better in the Fitnessgram battery, aerobic capacity and strength tests. In the Trunk Lift, and Sit and Reach tests, women exhibited greater flexibility.

Conclusions: It is important to evaluate the physical condition of schoolchildren, as a strategy for the prevention of chronic non-communicable diseases. In turn, it is recommended that the regular practice of physical activity be promoted in the school and home environment, as a protective factor of health.