Physical fitness and maternal body composition indices during pregnancy and postpartum: the GESTAFIT project

We explored the association of physical fitness (PF) during pregnancy with maternal body composition indices along pregnancy and postpartum period. The study comprised 159 pregnant women (32.9 ± 4.7 years old). Assessments were carried out at the 16th and 34th gestational weeks (g.w.) and six weeks postpartum. Cardiorespiratory fitness (CRF), muscular strength (absolute and relative values) and flexibility were measured. Body composition indices were obtained by using dual-energy X-ray absorptiometry at postpartum. The results, after adjusting for potential covariates at the 16th g.w., indicated that greater CRF was associated with lower postpartum indices total fat mass, android and gynoid fat mass (all, p < 0.05). Greater absolute upper-body muscular strength was associated with greater pre-pregnancy body mass index (BMI), gestational weight gain (GWG); and postpartum indices body weight, BMI, lean mass, fat free mass, fat mass, gynoid fat mass, T-score and Z-score bone mineral density (BMD) (all, p < 0.05). Greater upper-body flexibility was associated with lower pre-pregnancy BMI; and postpartum indices body weight, BMI, lean mass, fat free mass, fat mass, android fat mass and gynoid fat mass, and with greater GWG (all, p < 0.05). At the 34th g.w., greater CRF was additionally associated with greater postpartum T-score and Z-score BMD (both, p < 0.05). In conclusion, this study reveals that greater PF levels, especially during early pregnancy, may promote a better body composition in the postpartum period. Therefore, clinicians and health promoters should encourage women to maintain or improve PF levels from early pregnancy.