Prevalencia de sobrepeso e obesidade em escolares entre sete e 10 anos de idaade da Rede Municipal de Porto legre - RS

Physical activity is recognised to be an effective strategy to improve children’s health and reduce the risk of developing chronic diseases; osteoporosis and obesity being two examples with particularly high morbidity and mortality. An exercise program to improve both bone and reduce fat would be ideal. Problematically, bone is known to respond primarily to brief bouts of high impact activity, while the traditional exercise recommendation to reduce fat is longer duration, low to moderate intensity aerobic activities. The overall aim of the current work was to develop a novel exercise program for pre and peripubertal children to improve bone and minimise the accumulation of fat.

The thesis describes four studies, presented as one published manuscript, two in press and another under review. In the first study, we conducted a comprehensive systematic review, to determine the effects of previous bone-targeted programs on bone, muscle and fat in school age children. Meta-analyses were conducted to quantify the findings of the sixteen studies included in the review. From the meta-analyses, we concluded that improvements in fat have previously been observed as secondary benefits of bone-targeted in-school exercise programs.
The subsequent study, described in papers two and three, examined the CAPO Kids exercise program, which was specifically developed to improve indices of cardiovascular and metabolic health, bone, muscle and fat, and physical performance of pre and peripubertal boys and girls. The program was a nine-month, cluster randomised controlled exercise intervention, incorporated into the school schedule of Year 5 and 6 students three times per week, for ten minutes per session. Activities comprised high-intensity jumping and capoeira, a Brazilian sport that combines martial arts with dance. All participants were assessed before and after the 9-month program. We found that the CAPO Kids participants improved parameters of bone health as well as waist circumference, estimated maximal oxygen consumption and resting heart rate.

The final study was an observational examination of the metabolic and mechanical loads associated with the CAPO Kids activities. We determined energy expenditure during a 10-minute CAPO Kids session, and ground reaction forces of eleven CAPO Kids manoeuvres, in a sub-group of participants. We found that the CAPO Kids intervention indeed appears to generate sufficient metabolic and mechanical loads to simultaneously promote healthy adaptations in fat and bone.

Overall, the current thesis demonstrates the potential for positive effects of a bone-targeted exercise program on both metabolic and musculoskeletal health outcomes of pre and peripubertal children. Furthermore, CAPO Kids was a simple, appealing and feasible program, able to be implemented during school time, without disrupting the normal academic schedule. Based on these findings, we conclude that future translation of brief high intensity impact exercise programs into the school system more broadly holds promise for paediatric health and chronic disease prevention.