Impact of heavy resistance training on pregnancy and postpartum health outcomes

Introduction and hypothesis Participation in Olympic weightlifting, the Valsalva maneuver, and acute or prolonged supine weightlifting during pregnancy are cautioned against; however, these recommendations are based on expert opinions as opposed to empirical evidence. The aim of this study was to examine the training and health outcomes of individuals who engaged in heavy resistance training during pregnancy. Methods A total of 679 individuals who lifted at least 80% one-repetition maximum during pregnancy participated in an online survey. Results Participants were primarily recreational athletes (88%, 332 out of 675) engaged in CrossFit™ (61%, 410 out of 675) and/or weightlifting (49%, 332 out of 675) during pregnancy. Most participants reported no complications during pregnancy or delivery (66%, 388 out of 589), whereas 57% (241 out of 426) reported urinary incontinence following pregnancy. Participants who maintained pre-pregnancy training levels until delivery reported significantly less reproductive complications than those who ceased training levels prior to delivery ( p = 0.006). Most respondents engaged in Olympic lifting (72%, 311 out of 432) and lifting in a supine position (71%, 306 out of 437), whereas fewer reported use of the Valsalva maneuver during pregnancy (34%, 142 out of 412). Most returned to weightlifting following delivery (89%, 400 out of 447, average: 3.2 ± 3.0 months), including Olympic lifting (81%, 300 out of 372, average: 4.0 ± 3.4 months) and Valsalva (62%, 213 out of 341, average: 4.5 ± 3.6 months). Conclusions Individuals who engaged in heavy prenatal resistance training had typical perinatal and pelvic floor health outcomes that were not altered whether they engaged in, or avoided Olympic lifting, Valsalva or supine weightlifting.