Pregnancy is an ideal time to start or continue healthy lifestyle habits like exercise. Years ago exercise during pregnancy was thought to be “dangerous.” Women were advised to “avoid all strenuous exertion.”
Thankfully a lot has changed. Exercise in uncomplicated pregnancies is now recognized for its numerous benefits for both mom and baby. The following suggestions are meant to help you design a safe and rewarding exercise program before or during your pregnancy. In healthy pregnancies, exercise does not increase the risk of miscarriage, premature delivery, poor fetal growth or skeletal muscle injury.
Benefits of Exercise During Pregnancy
• Increased fitness for the “work of labor and delivery” as well as carrying around a new baby
• Lower risk of gestational diabetes
• Lower risk of cesarean section and vacuum-assisted delivery
• Lower risk of pre-eclampsia
• Decreased likelihood of varicose veins
• Faster return to pre-pregnancy fitness and weight
• Improved sleep
• Reduced back pain
• Decreased constipation
Body Changes in Pregnancy
Your body changes to prepare you for delivery and support the growing fetus. Body changes you may notice include: loosening joints, weight gain, major shifts in your center of gravity (balance), and breathing difficulty. To stay healthy during pregnancy, adapt your workouts to accommodate these major changes.
The hormone changes in pregnancy cause ligaments around joints to become looser so you may need to avoid high-impact and jerky or bouncy type exercise.
Weight gain and shift in your center of gravity can cause you to more easily fall so be sure to adapt your exercise to accommodate for this to lessen the chance of injury.
When you exercise, oxygen and blood flow are directed to your muscles and away from other areas of your body.
While you are pregnant, your need for oxygen increases. As your belly grows, you may become short of breath more easily because of increased pressure of the uterus on the diaphragm (a muscle that aids in breathing). These changes may affect your ability to do strenuous exercise, especially if you are overweight or obese.
How much exercise is recommended?
According to the American Congress of Obstetricians and Gynecologists (ACOG), you should include 150 minutes of moderate intensity aerobic exercise per week. 30 minutes per day, 5 days a week is reasonable for most people. Moderate intensity usually means you can talk but cannot sing during the activity. If you are new to exercise, you may even start with 5-10 minute sessions and build from there. If you were very active prior to pregnancy you should be able to continue exercise to maintain a healthy pregnancy, but if you start to lose weight, you may need to eat more calories.
What Medical Conditions Make Exercise Unsafe During Pregnancy?
Women should not exercise if they have the following complications during pregnancy.
• Certain types of heart and lung diseases
• Cervical insufficiency or cerclage
• Being pregnant with twins or triplets (or more) with risk factors for preterm labor
• Placenta previa after 26 weeks of pregnancy
• Preterm labor or ruptured membranes (your water has broken) during this pregnancy
• Preeclampsia or pregnancy-induced high blood pressure
• Severe anemia
5 Tips for Exercise During Pregnancy
1) Adjust your goals: Rather than focusing on gaining muscle and losing weight, aim to maintain fitness and gain a healthy, but not excessive, amount of weight.
2) Keep track of your body temperature: Hydration and workout environment are the most important strategies for temperature control. Keep your body temperature under 100.4 degrees, especially in the third trimester. Try exercising in a temperature-controlled area and avoid exercising in hot or humid conditions (including hot yoga, hot tubs, saunas). Have a goal of drinking 2-5 cups of water per hour of workout.
3) Keep track of your heart rate: You should be able talk without getting short of breath. This is less than 70-75 percent of your maximum heart rate (estimated by HR max = 220-age). If you already perform a high volume of exercise, you can continue up to nine hours of exercise per week.
4) Modify your workouts as your body changes: Exercise should be comfortable. Major changes occur to your center of gravity and joint laxity during pregnancy. Therefore, choose activities with low joint stress such as swimming, stair climbing, walking, elliptical and stationary bikes.
5) Weight training is OK: Contrary to popular belief, weight training can be very beneficial as long as you follow some principles:
• Breathe naturally. Avoid the Valsalva maneuver. This occurs when you exhale without letting air out. The Valsalva maneuver may temporarily decrease blood and oxygen flow to the baby.
• Work your core. Your core includes stabilizing muscles from your lowest rib to your knees. These muscles are on your front, side and back of your body, not just your abs! Back and hip pain tend to increase during pregnancy, exercises that brace the core can reduce pain.
• Use your muscles rather than momentum. Try not to “jerk” weights up, rather lift in a controlled way, being mindful of maintaining your core support.
• Decrease weight and increase reps: A good goal is 10-15 reps at 65-75 percent maximum lifting potential. This level helps maintain natural breathing and decreases stress on joints.
AMSSM Member Authors
Jeremy Johnson, MD
