After nutrition (“Eating for Two: Nutrition in Pregnancy” August 1, 2024), the next most important modifiable behavior during pregnancy is exercise.
Although many factors influencing pregnancy health are beyond our control, exercise is an area where we can have a substantial impact on outcomes. Exercise offers many benefits to a pregnancy including maintaining healthy maternal weight gain, lowering the risk of gestational diabetes and blood pressure disorders, reducing fetal size, increasing vaginal delivery rates, reducing cesarean deliveries, decreasing postpartum recovery time, and alleviating many of the aches and pains common to pregnancy.
The vast majority of pregnant women can engage in some form of exercise, although there are some who cannot due to medical or pregnancy complications. This is best discussed with your doctor on an individual basis because it can vary widely.
One common misconception is that reduced activity or bedrest will reduce the chance of preterm delivery. There is no evidence to support bedrest in most pregnancies for preventing early delivery and it should not generally be recommended. Bedrest also has downsides including deconditioning and increasing the risk of blood clots. Severely limiting physical activity can have significant negative psychological effects as well.
It is commonly advised to keep exercise to less than 80% of someone’s capacity (for many this translates to a maximum heart rate of about 140 beats per minute). This can vary based on how active someone is prior to pregnancy. The general recommendation is to aim for about 150 minutes of exercise per week broken up across days. A woman who did not exercise prior to pregnancy can start exercising while pregnant and gradually build up her tolerance over time.
Individuals who are highly active prior to pregnancy can often maintain their level of physical activity provided that they are not experiencing any negative effects (for very intense athletes this may have to be dialed back somewhat).
There are many forms of exercise that are safe in pregnancy. Walking, stationary bike, aerobic, dance, weights, stretching and water exercise are all well studied and safe. Water can be especially good because it is gentle on joints. Yoga is also an excellent choice for exercise in pregnancy.
There are some limitations and modifications necessary during pregnancy. Due to changes in back curvature and center of gravity, balance can become more challenging, so activities requiring excellent balance may not be suitable later in pregnancy. Lying on your back for extended periods can cause lightheadedness or shortness of breath in the second half of pregnancy, so some activities may need to be abbreviated or modified to side-lying positions. Contact sports (basketball, kickboxing, etc.) are not recommended and biking is discouraged due to the risk of falls and accidents.
During pregnancy dehydration and low blood sugar can occur more rapidly than women may normally experience. It is essential to hydrate and eat properly prior to exercising and to keep adequate fluids and snacks on hand during exercise. More frequent breaks might be necessary compared to pre-pregnancy routines.
Certainly, there are warning signs that may require the cessation of exercise. These include bleeding, abdominal pain or contractions, shortness of breath at rest, dizziness, chest pain, and muscle weakness. If any of these should occur, exercise should be discontinued until speaking with your doctor.
Exercise provides numerous benefits during pregnancy and can be an excellent opportunity to start a new fitness regimen, even for those who were not previously active. When performed appropriately, exercise can help manage many pregnancy challenges. Many personal trainers and coaches have extensive experience working with pregnant women. The key is to listen to your body and be patient with yourself. Although your body may not perform as it did before pregnancy, any amount of exercise is beneficial.
Dr. Jonathan (Yoni) Ratzersdorfer is a board-certified OB/GYN who has been in practice in New Jersey since 2015. He is a strong believer in supporting women’s birth choices to achieve the birth they desire. He is a physician at Maternal Resources, a thriving boutique style practice, with offices in Hackensack, Jersey City, Hoboken, Howell and New York City.
