The goal of this study is to assess the effect of exercise on plasma BCAA and acylcarnitine concentrations in women with obesity from early to late pregnancy. Findings will provide preliminary data and rationale for a future study that will assess the impact of an exercise intervention during pregnancy on amino acid and fatty acid metabolic fluxes using novel, precise technologies (e.g., stable isotope technology) in obese women to determine if exercise during pregnancy protects against
changes in circulating metabolites that are known to be associated with comorbidities of obesity (e.g., gestational diabetes mellitus). The specific objective of the proposed research is to test the hypothesis that exercise will elicit no effect on BCAA concentrations, but will attenuate the increase in acylcarnitine concentrations that is characteristic of the progression of pregnancy in obese women, and these changes will be related to an attenuated decrease in insulin sensitivity throughout pregnancy.