An approximate 10% of women engage in resistance training during pregnancy; however there is limited research on this activity. The purpose of this study was to examine associations between resistance training and adverse outcomes. Women completed an online survey and recalled their exercise habits during each trimester of their most recent pregnancy within the previous 5 years. Women also reported pregnancy and birth outcomes. Participants were then categorized into 3 groups based on leisure-time exercise: 1) Resistance + aerobic training (RTAE), 2) Aerobic exercise only (AE), and 3) no exercise (NE). 284 women completed the survey. Women in the RTAE group resistance trained on average 2.9 days/week for 27.3 minutes/session. The prevalences of hypertensive disorders (HD) and gestational diabetes mellitus (GDM) were significantly lower in the RTAE group when compared with the grouping of AE + NE women. Prepregnancy body mass index (BMI) was the strongest factor related to both GDM and HD. There wasn’t any difference in the risk of preterm labor, mode of delivery, or gestational age at delivery by exercise status.
These findings indicate that women can safely engage in aerobic exercise and resistance training for muscular endurance 3 days/week for 30 minutes throughout gestation.