Effects of Exercise on Pregnancy

The Positive Effects:

  • Exercise during pregnancy helps to alleviate many of the common problems of pregnancy. It improves circulation (which helps prevent constipation, hemorrhoids, varicose veins, leg cramps, and swelling of the ankles). It also prevents back pain by strengthening the muscles that support the back.
  • Pregnancy often leaves women feeling less energetic, but regular exercise can give you more energy to make it through the day. Your strengthened cardiovascular system will give you more endurance, and stronger muscles will allow you to accomplish tasks with less effort, leaving you more energy to continue through the rest of your day.
  • Exercise also allows you to sleep better. Most women have some trouble sleeping through the night by the end of their pregnancy. Exercising on a regular basis (and making sure it’s at least three hours before you go to bed) will help you work off excess energy, and will tire you enough to lull you into a deeper, more restful slumber.
  • Exercise has been shown to improve your mood, lessen mood swings, improve your self-image, and allow you to feel a sense of control when so much of your world and body feels out of control.
  • Exercise helps prepare your for childbirth. Some studies suggest that the fitness of the mother results in shorter labor, fewer medical interventions, and less exhaustion during labor. Being in shape will not decrease the pain, but it definitely will help give you the endurance needed to get through labor and be able to bounce back more quickly.
  • Most experts agree that gaining more than the recommended 25 to 35 pounds (for a woman of normal weight) during pregnancy makes it harder to lose the weight after the baby is born. By maintaining your fitness level during pregnancy, you are less likely to gain excess weight, and since exercise maintains your muscle tone and strength, it also makes it easier to bounce back after the baby is born.

The Problems to watch out for:

  • Check with your doctor or midwife before starting an exercise program. For most pregnant women, exercise is very beneficial, but for women who have a high-risk pregnancy or are at risk for pre-term labor, exercise should be closely monitored by your healthcare provider to make sure that the exercise poses no additional threats to you or your baby.
  • When you exercise, the blood flow shifts away from your internal organs (including your uterus) to give your muscles, lungs and heart more oxygen. If you exercise too strenuously, you can take oxygen away from your uterus. Make sure to stick within a recommended heart rate level to ensure that your baby is getting the oxygen he or she needs.
  • As your pregnancy progresses, your center of balance shifts, making falls more likely. Participate in activities (such as swimming, walking or low-impact aerobics) that do not put you at additional risk for slipping or falling. Avoid such activities as downhill skiing, horseback riding, mountain climbing, and contact sports (like football or soccer) that could put you at risk for injury or a fall.
  • Exercise causes an increase in your body temperature, which may effect the baby’s development. Use caution when exercising in hot weather and always make sure that you’re getting plenty of fluids when exercising. Your body temperature should stay below 101°F

“Exercise During Pregnancy,” The American College of Obstetricians and Gynecologists. 1998.
“Exercise,” The University of Michigan Health System. smartmoms.org. 2002.
“Pregnancy and Exercise: What You Can Do for a Healthy Pregnancy,” The American Academy of Family Physicians. familydoctor.org. 2002.
“Exercising During Pregnancy,” The Nemours Foundation. kidshealth.org. 2002.

Last updated: 12/2006