Factors related to exercise over the course of pregnancy including women's beliefs about the safety of exercise during pregnancy
Introduction
Increasing evidence supports the importance of exercise for individual health. Being active can reduce the risk of diseases such as osteoporosis (Welten et al., 1994), cardiovascular disease (Berlin and Colditz, 1990), type II diabetes (Manson and Spelsberg, 1994; Macdonald et al., 2006), colon cancer (Slattery et al., 1997), and obesity (Cortright et al., 2006). Regular exercise has also been shown to be effective in managing stress (Simonsick, 1991), alleviating depression (Morgan, 1994; Bartholomew et al., 2005; Galper et al., 2006), boosting self-esteem (Simonsick, 1991) and enhancing body image (Williams and Cash, 2001; Suris and Parera, 2005).
An awareness that exercise is important in promoting health and well-being has led to many women wanting to continue exercising during pregnancy (Da Costa et al., 2003). Traditionally, pregnant women have been advised to restrict exercise due to concerns for the health of the mother and her fetus, including risks of over heating; impaired delivery of oxygen and nutrients to the fetus; and premature labour (American College of Obstetricians and Gynaecologists, 1985). While no study has found any negative effect of moderate intensity aerobic exercise on pregnancy outcome in a normal, healthy pregnancy (Lokey et al., 1991; Bell et al., 1995; Sternfeld et al., 1995), the safe limits for exercise during pregnancy have not been determined.
The American College of Obstetricians and Gynaecologists (ACOG) guidelines for exercise during pregnancy aim to assist practitioners involved in the management of pregnant women, and the women themselves, in considering risks and benefits of exercise during pregnancy and deciding about participation. The 1985 ACOG guidelines recommended against vigorous exercise during pregnancy for previously sedentary women and those with adverse symptoms during pregnancy. Other women were advised to limit high impact activity, exercise intensity (⩽140 beats/min), and exercise duration (⩽15 min sessions). More recent ACOG guidelines (2002) acknowledged that participation in a range of exercise and recreational activities appeared to be safe during pregnancy. However, pregnant women were advised that each activity should be reviewed individually for its potential risk. If no medical or obstetric complications were present the guidelines recommended 30 min or more of moderate exercise on most, if not all, days. The guidelines acknowledged that there was little information available regarding vigorous exercise and women were advised to consult their health practitioners if considering strenuous exercise during pregnancy.
It has been suggested that uncertainty surrounding the safety of exercise during pregnancy leads women to stop or reduce exercising because of concerns for their unborn child (Ezmerli, 2000; Clarke and Gross, 2004) and increased risk of maternal falls and injury (Clarke and Gross). However, we are not aware of research that has examined whether there is an association between pregnant women's beliefs about the safety of exercise and their levels of exercise participation during pregnancy.
Therefore, this prospective study followed women across pregnancy, to examine their beliefs about the safety of exercise during pregnancy and whether these beliefs were associated with the amount or the intensity of exercise engaged in over time. The study also explored the amount and intensity of exercise that women participated in across pregnancy and reasons women reported for exercising or not exercising during pregnancy.
Section snippets
Method
In this study, women in the early phases of their pregnancy were recruited from the general population and completed questionnaires and a 1-week exercise diary at 16–23-weeks gestation (T1), 24–31-weeks gestation (T2), and 32–38-weeks gestation (T3). Approval for this study was obtained from the La Trobe University Human Ethics Committee. The study reported here was part of a larger project on women's experiences across pregnancy—only measures relevant to this study are described here.
Sample characteristics
Table 1 depicts demographic characteristics of participants. At T1 the 158 women had an age range from 21 to 42 years and were from 16 to 23-week gestation with a mean of 18.5 weeks. Most participants were from Melbourne and regional Victoria, Australia, with several residing in other states. At T2 152 women returned the questionnaires; mean gestation was 26.6 weeks (range=24–31 weeks). At T3 144 women returned questionnaires; mean gestation was 34.5 weeks (32–38 weeks).
Internal consistency of intensity measure
Internal consistency of
Discussion
The aims of this study were to examine women's beliefs about the safety of exercise and reasons for exercising or not exercising during pregnancy. Four factors of exercise safety beliefs were created: safety beliefs related to low to medium exercise, high intensity exercise, gentle exercise, and weight bearing exercise. Overall, most women believed that low intensity exercise and low impact exercise were safe and that high puff vigorous exercise and high impact exercise were unsafe. Women with
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