Exercising While Pregnant – Should I or Shouldn’t I?

Mandy is a 30-year-old woman who is currently 5 weeks pregnant with her first child. While she is very excited about starting her family with her husband Nick, she is concerned about what she should and should not be doing for physical activity. Her mom has been encouraging her to rest as much as possible and cautioned her against her usual three times per week gym routine. She has not been able to see her gynecologist yet as her appointment isn't scheduled for another week. She has been reading online but there seems to be a variety of opinions. Some caution against exercise while others promote it, which has been very confusing. Amanda is not alone in her confusion, as pregnant women often receive a variety of recommendations regarding exercise and physical activity while pregnant. This can lead to a fear of movement, as mothers do not want to place their unborn babies at risk. So, let's dive into the current recommendations and give moms like Mandy a little peace of mind!

According to The American College of Obstetricians and Gynecologists (ACOG) April 2020 Committee Opinion, "physical activity in pregnancy is safe and desirable, and pregnant women should be encouraged to continue or to initiate safe physical activities". Additionally, "Physical activity and exercise in pregnancy are associated with minimal risks and have been show to benefit most women". Of course, if there is an individual medical concern or complication, that may alter a particular individual's exercise or physical activity abilities.¹

There are many benefits to exercising while pregnant, including decreased maternal obesity, decreased gestational diabetes mellitus, decreased gestational hypertension (preeclampsia), reduced likelihood of unplanned cesarean birth, reduced operative vaginal delivery (instrument assisted), and reduced postpartum recovery time. There is a higher likelihood of vaginal delivery and it is essential in the prevention of postpartum depressive disorders. Furthermore, the idea that physical activity during pregnancy can cause miscarriage, poor fetal growth, injury, or premature delivery have not been proven in women with uncomplicated pregnancies. ^1-2 Unfortunately, only about 23% of pregnant women were meeting the ACOG Physical Activity Guidelines as of 2015.³

Aerobic activity has been found to increase aerobic capacity in normal and overweight pregnant women. Current aerobic activity recommendations are 150 minutes of moderate intensity aerobic activity that is spread throughout the week during pregnancy and the postpartum period. If a woman has already engaged in vigorous-intensity aerobic activity prior to pregnancy, she can continue to do so. Thirty to sixty minutes of aerobic activity 3-7 times per week have specifically been shown to be beneficial in reducing preterm birth, preeclampsia, and lowering glucose levels in those with gestational diabetes. ¹

Exercises that have been found to be safe and beneficial in pregnancy include walking, stationary cycling, aerobic exercise, dancing, resistance exercise (lifting weights), stretching, and water aerobics. ¹ In fact, the Australian guidelines for physical activity in pregnancy and postpartum that were updated this year (2022), specifically recommends muscle strengthening at least 2 days per week. ² Strengthening can include equipment like machines, weights and resistance bands, as well as body weight exercises. Strengthening, like any other exercise, should be tailored to each individual's current ability level with appropriate progression and regression as needed. Keep in mind that modifications may be necessary due to the changes in a mother's body during pregnancy, which is an important component that a pelvic physical therapist can create based on your individual needs. ¹ Pelvic floor PTs can create workout programs that adjust to a pregnant female’s body depending on the trimester they are in and pregnancy related pain conditions, such as sciatica. For example, some women may experience hypotension (low blood pressure) if they lay flat on their back after 20 weeks because of anatomic changes that occur. In order to target certain muscle groups, alternative positions or exercises may be utilized that were not previously necessary for an individual. ¹

Along with possible changes in position with exercise, women may also notice respiratory and temperature regulation changes. It is important to remain hydrated, avoid high heat or humidity exercise environments, and wear loose clothing. Also, exercise greater than 45 minutes or high-intensity can lead to low blood sugar (hypoglycemia) so pregnant women should ensure good caloric intake before exercise. ¹

In addition to the importance of exercise, the Australian and Swiss guidelines include a recommendation to reduce prolonged periods of sitting by doing short durations of light activity. This encourages metabolic and circulatory benefits, such as reducing swelling in the legs and feet. ² Research already supports reducing prolonged sitting in non-pregnant individuals to reduce the risk of health conditions like diabetes and heart disease so this practice should be continued into pregnancy. An easy tip to incorporate position change, especially for you mamas that have sitting based jobs, is to set a timer on your phone or use a fitness watch that reminds you to stand. You won't have to worry about becoming too engrossed in your work or being too conscious of the clock - your phone or watch will do it for you!

The ACOG does recommend that women receive a thorough examination to ensure that there is no medical reason to avoid exercise. Once cleared, a patient should work with a professional (reach out to your local pelvic floor physical therapist!) to develop an individualized program. Aside from developing a program based on your individual strengths and weaknesses, a professional can help you develop certain parameters to ensure you are achieving the appropriate level of exertion during exercise. For example, if a pregnant woman can carry on a conversation while exercising than she is likely not over-exerting herself. This is known as the "talk test". Keep in mind that your level of exercise prior to pregnancy will also dictate the intensity and progression of exercise while pregnant. ¹

If you are currently exercising while pregnant and experience particular symptoms, you should stop exercise and seek out further medical follow up. These symptoms include vaginal bleeding, abdominal pain, regular painful contractions, amniotic fluid leakage, difficulty breathing before exertion, dizziness, headache, chest pain, muscle weakness affecting balance, and calf pain or swelling. Interestingly, bed rest to prevent preterm labor has no credible evidence and should not be routinely prescribed. There is also no evidence that bed rest reduces preeclampsia risk. ¹

In summary, unless you are experiencing medical concerns and your physician specifically advises against it, exercise has numerous health benefits during pregnancy! While modifications may be needed as your body changes, there is no reason you should not be able to continue enjoying your current level of activity. Also, if you have not been active in the past, pregnancy is a wonderful time to start implementing healthy habits! After all, you are being healthy for two now. If you are feeling overwhelmed, unsure of how to start, curious about modifications, or looking for a watchful eye to ensure appropriate form with an ever-changing body, reach out to your local pelvic floor physical therapist! Keep in mind that they can not only assist with creating an individualized plan for you, but they can also address low back, hip, pelvic, and other orthopedic concerns as your pregnancy progresses including pain or incontinence. You do not have to figure it out on your own!

Written by Jordan Schmidt, PT, DPT

References

1. Syed, H., Slayman, T., & DuChene Thoma, K. (2021). ACOG Committee Opinion No. 804: Physical Activity and Exercise During Pregnancy and the Postpartum Period. Obstetrics and gynecology, 137(2), 375–376. https://doi.org/10.1097/AOG.0000000000004266
2. Brown, W. J., Hayman, M., Haakstad, L., Lamerton, T., Mena, G. P., Green, A., Keating, S. E., Gomes, G., Coombes, J. S., & Mielke, G. I. (2022). Australian guidelines for physical activity in pregnancy and postpartum. Journal of science and medicine in sport, 25(6), 511–519. https://doi.org/10.1016/j.jsams.2022.03.008
3. Hesketh, K. R., & Evenson, K. R. (2016). Prevalence of U.S. Pregnant Women Meeting 2015 ACOG Physical Activity Guidelines. American journal of preventive medicine, 51(3), e87–e89. https://doi.org/10.1016/j.amepre.2016.05.023