The overall objective of this proposal is to conduct a longitudinal prospective study of healthy pregnant women and their offspring to determine which antenatal maternal exercise mode(s) will have the greatest impact on maternal and infant cardiometabolic health. This information may lead to modified clinical practice recommendations that improve health in childhood and possibly beyond. This randomized controlled trial will recruit 268 healthy pregnant women randomized to an exercise intervention (aerobic exercise, resistance exercise, aerobic and resistance exercise) or to no exercise (usual care); their infants will be measured at 1, 6, and 12 months of age. This rigorous design will test our central hypothesis that aerobic and resistance exercise and resistance exercise training during pregnancy will, in healthy weight BMI (HW) women, improve maternal and offspring cardiometabolic outcomes to a greater extent than AE alone. We will test this hypothesis with two specific aims: Aim 1. Determine the influence of different exercise modes during HW pregnancy on infant cardiometabolic health and growth trajectories. Hypothesis: AE, RE, and AERE by HW pregnant women will improve offspring neuromotor and cardiometabolic measures at 1, 6, and 12 months postpartum (e.g. decreased % body fat, BMI z-score, heart rate, non-HDL, and C-Reactive Protein (CRP); increased insulin sensitivity) compared to infants of HW pregnant women that do not exercise; AERE and RE will have the greatest impact on improving infant measures. Aim 2. Determine the most effective exercise mode in HW pregnancy on improving maternal cardiometabolic health outcomes. Hypothesis: AE, RE, and AERE by HW pregnant women will improve both maternal cardiometabolic health measures (e.g. decreased BMI z-score, non-HDL, % body fat, HR, weight gain) across pregnancy (16 to 36 weeks gestation) and overall pregnancy outcomes (e.g. lower incidence of gestational diabetes, pre-eclampsia, hypertension during gestation) compared to HW pregnant women that do not exercise; AERE and RE will have the greatest impact on improving maternal health measures, with the AERE group having the highest compliance. The proposed innovative study will be the first to provide a critical understanding of the influence of antenatal exercise modes upon the cardiometabolic health and growth trajectories of offspring who may be at increased risk of poor outcomes. This work will have a significant impact on reducing the cycle of OB and CVD, potentially providing the earliest and most efficacious intervention to attenuate or prevent OB and CVD in the next generation.