Dispelling Myths: Exercise During Pregnancy

Should pregnant women exercise? 

While exercise is typically encouraged in all stages of pregnancy, women should consult with their healthcare provider before starting or continuing an exercise routine, especially if they have any pre-existing conditions or pregnancy-related complications. Caloric intake should be adjusted appropriately when exercising while pregnant to ensure both mother and baby are getting the needed nutrients and calories to remain healthy. The good news is that research shows that exercise during pregnancy is beneficial for both mother AND baby. According to Berghella and Saccone (2017), physical activity while pregnant is linked to successful vaginal delivery, less excessive weight gain for expecting mothers, lower rates of gestational diabetes and preeclampsia, less frequent pre-term birth, and healthy birth weight for babies. There is no evidence to suggest that women should wait until the second trimester to begin exercising. In fact, the sooner pregnant women begin exercising, the greater the benefit to mother and baby. In addition to the physical benefits mentioned, there are numerous mental health benefits for women who exercise while pregnant. Exercise boosts endorphins which can help reduce stress, anxiety, and the risk of prenatal and postpartum depression. While it seems counterintuitive, exercise can increase energy levels, aid in better sleep, and reduce pregnancy discomforts. 

Physical activity during pregnancy is not shown to increase risk of miscarriage. A 2023 Barakat systematic review analyzed 3,700 pregnant women across 13 studies to determine if low to moderate intensity exercise increased risk of miscarriage. Moderate intensity across these studies was defined as 55-65% of perceived maximum maternal heart rate, or perceived medium effort. Types of physical activity included yoga, pilates, aerobic activities, strength training, and pelvic floor exercises. Women who exercised were compared with women who did not exercise. There was no increased rate of miscarriage in women who exercised.  

How much should pregnant women exercise? 

Standard guidelines suggest 150 minutes of moderate level intensity exercise spread out over several days per week to provide a benefit. Exercising more frequently, 5 days or more per week, has shown increased benefit to mother and baby. This is the case for mothers of healthy weight as well as mothers who are overweight or obese. A 2024 Claiborne study found that an intensity of 85% of maximum heart rate does not harm the baby and even decreases likelihood of premature birth. In principal, mothers can expect to reap what they sow. Exercising more frequently and with higher intensity is likely to yield more positive results. Claiborne also found that greater exercise volume (i.e., total amount of training load) decreased the length of the baby’s hospital stay after birth.  

What type of exercise should pregnant women do? 

Claiborne et al. (2024) found that there are benefits to both strength training and aerobic activity. Strength training has shown to be of benefit to the placenta and, therefore, offering greater nutrient exchange to the baby. Aerobic activity alone and a combination of aerobic activity with strength training led to greater birth length in babies and baby leanness measured by weight to length ratio (i.e. ponderal index). Berghella and Saccone (2017) state that the following extensively studied types of exercise during pregnancy were found to be safe and beneficial: walking, stationary cycling, dancing, swimming, running, yoga, pilates, stretching, water aerobics, and resistance exercises with weights and elastic bands.  

Not only is exercise not harmful to a baby in the womb, it is beneficial for both mother and baby! If you are pregnant or are planning to become pregnant, talk to your doctor about how you can best incorporate exercise into your pregnancy.  

The Behavioral Health Wellness Environments for Living and Learning (BH WELL) research team exists to promote behavioral health and wellness among individuals facing behavioral health challenges. To learn more about BH WELL, visit our website. Interested in more evidence-based, free mental and behavioral health resources? Follow us @ukbhwell on Instagram, X, and Facebook