Maternal Physical Activity, Fitness, and Body Composition in Women with Gestational Diabetes: A Prospective Study.

Purpose: This study aimed to 1) describe perinatal changes in physical activity (PA), physical fitness (PF), and body composition (BC) and 2) investigate prospective associations between PA and PF, and between PF and BC in metabolically high-risk women with gestational diabetes mellitus (GDM).

Methods: This secondary analysis of the MySweetheart trial included 211 women with GDM. Outcomes were measured at 24 to 32 wk of gestational age (GA) and at 1 yr postpartum. Physical activity was measured using accelerometer and BC with bioelectrical impedance analysis (fat mass [FM], fat-free mass [FFM]) or dual-energy X-ray absorptiometry (FM, visceral adipose tissue [VAT], lean mass [LM]; postpartum only). Regarding PF, handgrip strength and cardiorespiratory fitness (CRF) were assessed, the latter using the Chester step test to estimate the maximal oxygen uptake (V̇O 2max ). Models were adjusted for sociodemographic variables and BMI where applicable.

Results: Between pregnancy and the postpartum, sedentary time decreased ( P < 0.001), whereas all PA intensities increased (all P < 0.001). CRF and handgrip strength did not change (both P ≥ 0.07), while FM and FFM decreased (both P < 0.001). Greater overall PA and moderate to vigorous PA during pregnancy were associated with better CRF and handgrip strength at 1 yr postpartum in unadjusted models only ( P < 0.05). Higher V̇O 2max was associated with lower FM and VAT, whereas higher handgrip strength was related to higher LM and FFM at 1 yr postpartum (all P < 0.001), before and after adjustments.

Conclusions: In high-risk women with GDM, higher PA during pregnancy correlated with greater PF at 1 yr postpartum only in the unadjusted, but not in the adjusted analyses. Higher PF levels were related to improved BC, highlighting their importance in the perinatal period.