The efficacy of moderate-to-vigorous resistance exercise during pregnancy: a randomized controlled trial

Objectives: To assess the effect and safety of moderate-to-vigorous resistance exercise during pregnancy.

Design: Randomized controlled study.

Setting: Two antenatal clinics in Gothenburg, Sweden.

Population: Ninety-two healthy pregnant women.

Methods: The intervention was administered during gestational weeks 14-25. The intervention group received supervised resistance exercise twice a week, performed at an activity level equivalent to within moderate-to-vigorous (n = 51). The control group received generalized exercise recommendation, a home-based training program and a telephone follow up (n = 41).

Main outcome measures: Health-related quality of life, physical strength, pain, weight, blood pressure, functional status, activity level, and perinatal data.

Results: Functional status deteriorated during the intervention in both groups and pain increased. Significant differences between the groups were obtained only for birthweight. Newborns delivered by women who underwent resistance exercise during pregnancy were significantly heavier than those born to control women; 3561 (±452) g vs. 3251 (±437) g (p = 0.02), a difference that disappeared when adjustment was made for gestational age (p = 0.059). Both groups showed normal health-related quality of life, blood pressure, and perinatal data.

Conclusions: These findings indicate that supervised, moderate-to-vigorous resistance exercise does not jeopardize the health status of healthy pregnant women or the fetus during pregnancy, but instead appears to be an appropriate form of exercise in healthy pregnancy.