Background:

Use of variable definitions of exercise and disparate results, emphasize the need of proper randomized controlled trials examining the relationship between physical activity and weight development during pregnancy. So far, only few intervention studies aiming at weight management during pregnancy have been performed (Gray-Donald et al., 2000,Olson et al., 2004,Polley et al., 2002,Kinnunen et al., 2007). Moreover, most of these interventions have focused on how gestational weight gain may be altered through individual counselling combining diet and exercise habits, rather than supervised training. Search on PubMed revealed no randomized controlled trial where the main outcome was to investigate how the effect of supervised structured exercise may reduce the proportion of women gaining more weight than optimal. The aim of the present study is to assess whether a 12-week aerobic exercise program during pregnancy can prevent excessive gestational weight gain.

Method:

This is a single blind randomized controlled trial to evaluate the effects of a structured, supervised aerobic exercise program on weight gain stabilization in primiparous pregnant women. The aim is to include 100 women. Interested women eligible for the present study will be invited to a pre-test including interview and assessments at the university. The women are examined three times during the study period. The first visit is between 12 and 24 weeks of gestation, the second at week 36-38 and the last 8-12 week after delivery. The exercise program consists of supervised exercise for 60 minutes, performed at least 2 times per week, for 12-16 weeks. Compliance with the training protocol is controlled by the instructors and registrations in the womens personal training diary