Pediatric obesity is a paramount public health concern that has reached epidemic proportions. Furthermore, youth from ethnic minority groups, including Latinos are disproportionately affected. Coupled with the increased prevalence rates of obesity in the pediatric population, are increases in the incidence of medical complications, such as the metabolic syndrome and type 2 diabetes. In adults, it is generally accepted that high levels of physical fitness / activity are protective against obesity related complications. However, a relative paucity of data exists in children to support these conclusions;​ especially as they pertain to youth from high-risk ethnic groups. Therefore, the purpose of this dissertation was three-fold:​ 1) to compare cardiovascular fitness levels among Caucasian, African-American, and Latino youth:​ 2) to examine the cross-sectional relations between cardiovascular fitness and metabolic risk factors in overweight Latino youth:​ and 3) to examine the effects of a 16-week resistance training exercise intervention on metabolic risk factors in overweight Latino boys.

In study I, cardiovascular fitness was significantly lower in both African-American and Latino youth compared to their Caucasian counterparts. Moreover, this finding was not explained by gender, maturational stage, or body composition. In study II, overweight Latino children with impaired glucose tolerance did not differ in fitness or activity compared to normal glucose tolerant counterparts. In study III, fitness in overweight Latino children was not independently associated with any individual feature of the metabolic syndrome. Moreover, children with the metabolic syndrome did not have lower fitness levels compared to those without the metabolic syndrome. In study IV, resistance training exercise significantly increased insulin sensitivity in overweight adolescent Latino males. The increased insulin sensitivity was not accompanied by concomitant improvements in either pancreatic [3-cell function or risk factors associated with the metabolic syndrome.

In summary, Latino youth exhibit lower fitness levels compared to Caucasians. However cross-sectionally, fitness does not appear to be an important independent determinant of metabolic health in these youth. Alternatively, resistance training appears to be a viable exercise intervention to improve certain aspects of metabolic health in this population. Whether improvements correspond to long-term reductions in disease risk requires further investigation.