In addition, generation of excess reactive oxygen species, known byproducts of lipid metabolism, may contribute to altered/abnormal oxidative stress profiles in obese pregnant women. Reactive oxygen species are up-regulated during physiologic pregnancy as well as non-gravid obesity, and research suggests oxidative stress may be related to poorer neonatal outcomes (Heerwagen 2010) . In non-gravid individuals, long-term physical activity has been shown to improve oxidative stress profiles (Fisher-Wellman 2009). Therefore, women who exercise during pregnancy may also have higher antioxidant capacity and lower markers of oxidative stress; both of which may contribute to favorable neonatal outcomes. However, this has not yet been studied.