Should I Run While Pregnant?
by Mario Fraioli
- May 11, 2010
- Comments Off
By Lewis G. Maharam, MD, FACSM
I just found out I’m pregnant! I am so excited. I usually run 30-40 miles per week. My husband says I need to stop running and my doctor, when I asked, was “on the fence” and said he couldn’t understand why I would want to run that much. I remember you once posted a comprehensive article about running when pregnant. Can you please re-post it so I can bring a copy to my doctor and we can all agree! Thanks. Gail C. Chicago, IL.
Thanks, Gail., for such an important question and I appreciate your remembering my posts!
Some people recommend stopping everything when pregnant; these are usually people without a firm knowledge of the topic. I actually wrote a chapter on this very subject in a medical textbook (Current Therapy in Sports Medicine 1985-1986, Welsh and Shepard, eds., B.C. Decker, Inc., Philadelphia 1985, pp. 122-125) while I was a medical student at Emory.
The best way to understand what you can and cannot do while pregnant is to understand the physiology.
Running Doc’s Pregnancy Physiology 101
The physiological changes a woman’s body goes through during pregnancy are very similar to those produced by strenuous exercise. Briefly, cardiac output increases by 30-50% over the non-pregnant resting state. The greatest cardiac output increase occurs during the first trimester when uterine blood flow is only slightly increased and before the placental vascular flow has begun. The maximal maternal blood volume is seen in the third trimester, giving the woman the ability to maximize cardiac output while working less.
Breathing rate (minute ventilation) during exercise also increases, especially in the third trimester. Because there is an increase in total body mass, additional oxygen is needed to perform any given activity.
Other normal physiological changes include a reduction of hematocrit and a slight increase in hemoglobin concentration. There are endocrine-based changes of carbohydrate and steroid metabolism. Curvature of the lumbar spine and relaxation of the cartilages of the symphysis pubis are also seen and normal.
In general, exercise brings about similar physiologic alterations. Changes are most pronounced for the cardiovascular and respiratory systems and less marked for the musculoskeletal and endocrine systems. If pregnancy and exercise are combined, there is a double physiologic impact. This very fact has led doctors, rightfully so, to recommend that if a prospective mother has not been involved in an exercise program prior to pregnancy, she should not be encouraged to begin one during her pregnancy!
Practical Recommendations
But you, Gail, currently run and should absolutely not be discouraged from running. We now know, with our emphasis on physical fitness, that exercise is good not only for the general health of the non-pregnant female, but also for the pregnant woman. Exercise helps assure an easier birth (in most cases) and a healthy fetus. Let’s discuss this by trimester, each of which has unique recommendations:
First trimester: Avoid hot baths, whirlpools, and saunas, as high temperature has been linked to birth defects. This is not the time to begin an exercise program, but for those exercising, do not change your routine. Summer exercise should be conducted in the cool morning hours, when there is light for outdoor activities but the temperature has not peaked; running after sunset when the temperature is cooler carries with it the increased risk of injury due to darkness. Do not over-exert – now is not the time to try for a marathon PR. The greatest cause of heat stroke (and raised body temperature during running) is pushing one’s self; take it easy, and hydrate appropriately. Finally, the mother should avoid medications, drugs, tobacco, and alcohol; medications should be taken only if deemed necessary and prescribed by a physician who knows you are pregnant.
Second trimester: All first-trimester recommendations continue. Also, the mother should now start strengthening muscles used in labor; time for the Kegels. Augment your diet with iron and calcium supplements as the developing fetus begins to demand these elements in increasing amounts. A good physical examination by an OB-GYN at this time is critical to determine the competency of the cervix. (The mouth of the uterus, which helps hold the baby inside.) A “weak” cervix is the most common contraindication for running from now until the baby is born. Don’t run after this exam without your practitioner’s OK.
Third trimester: Research has shown that continued running during third-trimester pregnancy is not harmful to the developing child. However, the mother should avoid exercises that may compromise fetal blood flow, particularly venous return: for example, standing in place for long periods of time and lifting heavy weights. Besides running, ideal exercises include yoga, walking, and swimming (until near term but certainly not after rupture of the membranes).
Postpartum
So now the baby has been born. What next? Depending on the type (and “normality”) of delivery, an exercise program should be resumed as soon as the mother and attending physician or nurse-midwife feel comfortable. Even while still in the hospital, the mother can begin to restore muscular tone to her abdomen and pelvis. This helps prevent urinary incontinence, uterine prolapse, and enhancing a return to normal sexual activity. Exercise also promotes blood flow, avoiding such complications as varicose veins, leg cramps, edema, and blood clot formation. Improved circulation promotes healing of traumatized pelvic tissues and strengthens uterine and pelvic ligaments and tendons. Kegel exercises to strengthen the pelvic floor are recommended.
As an added benefit, exercise in the postpartum period has been shown to decrease the incidence of postpartum depression. We all know how we feel if we don’t exercise, so get those endorphins kicking!
The major exercises to avoid postpartum are those that employ a knee-chest position. (E.g., squats, lying on your back bringing knees up, facing down on bent knees, etc.) There have been reported complications (neurological and vascular) with these positions, so stay away from these until your physician says it’s OK.
Gail, we at Competitor wish you and all the expectant running mothers out there a wonderful 9 months and a happy, healthy baby. You can tell your husband and your doctor, running will be best for you and your child.
Enjoy the ride!
Dr. Lewis G. Maharam is the world’s premier running physician. He is medical director of Competitor Group’s Rock ‘n’ Roll Marathon series throughout the country and The Leukemia & Lymphoma Society’s Team in Training program. He also serves as Chairman of the Board of Governors, International Marathon Medical Directors Association. Dr. Maharam “s column can be followed in Competitor Magazine and his Facebook page: Running Doc
Any questions you may want answered by Dr. Maharam in future columns should be e-mailed to Dr. Maharam at runningdoc@competitor.com.