Introduction: Walking may be a strategy for increasing moderate-intensity physical activity (MPA) during pregnancy.
Purpose: This study aimed to promote MPA among overweight and obese pregnant women, via walking, and to evaluate the effect of the intervention on maternal and birth outcomes.
Methods: Thirty-seven overweight or obese pregnant women were randomly assigned to a walking intervention or control group. Anthropometric and objective PA (StepWatch™ Activity Monitor) data were collected for four 1-wk periods: weeks 10–14 (V1), weeks 17–19 (V2), weeks 27–29 (V3), and weeks 34–36 (V4) of gestation. Participants provided information about maternal and birth outcomes. A cadence of ≥80 steps per minute was defined as MPA, and “meaningful walking” was defined as moderate walking in ≥8-min bouts. ANOVA was used to determine the differences in walking amount and meaningful walks, the Kolmogorov–Smirnov test was used for walking intensity distribution analysis, and Fisher’s exact test was used for maternal and infant outcomes analyses. Pearson correlation was used to examine the association between prepregnancy body mass index and gestational weight gain (GWG).
Results: There was significantly more MPA among women in the intervention group compared with those in the control group at V2 (overweight, P < 0.0001; obese, P < 0.025), V3 (overweight, P < 0.0001), and V4 (overweight, P < 0.0001; obese, P < 0.025). Women in the intervention group significantly increased their meaningful walks at V2 (P = 0.054), V3 (P = 0.01), and V4 (P = 0.014). There were trends for intervention group women to have more favorable maternal and birth outcomes compared with the control group. Rates of GWG at measurement points during pregnancy were significantly associated with preceding rates of GWG.
Conclusion: The pilot, unsupervised walking intervention increased the MPA of overweight and obese women during pregnancy.
1Department of Food Science and Human Nutrition, Iowa State University, Ames, IA; 2Interdepartmental Graduate Program in Nutritional Sciences, Iowa State University, Ames, IA; 3Department of Statistics, Iowa State University, Ames, IA; and 4Department of Kinesiology, Iowa State University, Ames, IA
Address for correspondence: Lorraine Lanningham-Foster, Ph.D., Department of Food Science and Human Nutrition, Iowa State University, 220 MacKay Hall, Ames, IA 50011; E-mail: email@example.com.
Submitted for publication June 2013.
Accepted for publication August 2013.