Prenatal physical activity paradox: occupational versus leisure-time physical activity

Physical Activity and High-Sensitivity C-Reactive Protein in Pregnancy: Does It Matter during Leisure or Work?

INTRODUCTION

Physical activity (PA), regardless of domain, is recommended for pregnant individuals in clinical guidelines, but limited evidence is available for work-related PA. This study aimed to examine the associations of occupational (OPA) and leisure-time PA (LTPA) with plasma high-sensitivity C-reactive protein (hs-CRP), a risk marker for adverse pregnancy outcomes, among pregnant individuals.

METHODS

This longitudinal study included 257 workers in the fetal growth cohort. OPA/LTPA and hs-CRP were measured in each trimester. OPA/LTPA was divided into high and low groups by the median level. Multivariable linear regressions were applied to estimate the adjusted geometric mean differences of hs-CRP (mg·L-1) comparing high versus low OPA/LTPA in each trimester and the changes in OPA/LTPA over pregnancy.

RESULTS

OPA was positively associated with hs-CRP (high: 5.14 vs low: 3.59; P value: 0.001) in the first trimester, particularly for standing/walking or walking fast, regardless of carrying things. LTPA was negatively associated with hs-CRP in the second (high: 3.93 vs low: 5.08; 0.02) and third trimesters (high: 3.30 vs low: 4.40; 0.046). Compared with the low OPA + high LTPA group, hs-CRP was higher in both the high OPA + high LTPA and high OPA + low LTPA groups in the first trimester, and in the high OPA + low LTPA group only in the third trimester. The change in OPA during pregnancy was positively associated with hs-CRP, whereas the change in LTPA was negatively associated with hs-CRP from the second to the third trimester.

CONCLUSIONS

In pregnant individuals, LTPA was negatively associated with hs-CRP, whereas OPA was positively associated with hs-CRP. More research on OPA's health impact among pregnant individuals is needed, and guidelines may consider the potential unfavorable influence of OPA on pregnant individuals.

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.