ABSTRACT
Regular physical activity is shown to lessen the burden of obesity-related comorbidities, including reductions in blood pressure, an increase in insulin sensitivity, and a decrease in hepatomegaly (Hassink et al., 2008; Martinez-Gomez et al., 2009; Shaibi et al., 2009; Sothern, 2004; Sothern et al., 1999a). Vigorous, intermittent physical activity is shown to reduce components of the metabolic syndrome in prepubertal children (Barbeau et al., 2007; Ben Ounis et al., 2010; Brambilla, Pozzobon, & Pietrobelli, 2011; Fedewa et al., 2013; Kahle et al., 1996; Nassis et al., 2005; Shaibi et al., 2006; Yu et al., 2005). Moreover, physical activity improves metabolic health in obese youth independent of adiposity change (Shaibi et al., 2009). Signicant improvements in body composition are associated with exercise programs, including low-to moderate-intensity aerobic and high-repetition strength training (LeMura & Maziekas, 2002). Regular physical activity reduces depression and improves mental health (Pretty et al., 2005), and childhood obesity is associated with depression (Erickson et al., 2000). Developmentally appropriate physical activity improves motor performance (Ildiko et al., 2007) and cognition (Bergen, 2002) in youth, and regular aerobic exercise improves cognitive and function in overweight children (Davis et al., 2007; Davis et al., 2011). Regular participation in exercise reduces inammatory cytokines (Radak, Chung, & Goto, 2008), and childhood obesity is associated with inammation and asthma (Arshi et al., 2010; Goran & Sothern, 2005). Chronic exercise training increases skeletal muscle glycogen content and enhances fat oxidation, thus promoting fat as a fuel source over carbohydrates (Pedersen & Fischer, 2007; Tompkins et al., 2009). Furthermore, physical activity lifestyle changes positively alter satiety factors in youth (Balagopal et al., 2010). In contrast to these outcomes of regular physical activity, chronic sustained periods of muscular unloading (sitting, lying) reduce contractile stimulation and suppress muscle lipoprotein lipase activity, triglyceride and glucose uptake, and high-density lipoproteins production (Bey & Hamilton, 2003; omas et al., 2005).
