Exercising Through Pregnancy
Written by Kristen Miller
To exercise or not to exercise? That is the question. Should there be any question as to whether or not woman should exercise during pregnancy? I think not. The Academy of Obstetrics and Gynecology thinks not, too.
In the past ten years there has been advancing research conducted on exercise during pregnancy. This is due in part to a higher percentage of women wanting to become or remain active during pregnancy and a lack of conclusive research existing in this area. Ten years ago health care providers tended to use conservative guidelines for exercise during pregnancy, as did national agencies such as the American College of Obstetrics and Gynecology (ACOG). Present research has changed those views and guidelines are now much more liberal for uncomplicated pregnancies.
The physiological changes that occur during pregnancy are well known but the effect of exercise on these changes is just beginning to be understood. Many of the previously believed negative effects of exercise during pregnancy (neural tube defects, pre-term labor and fetal nutrition) have been disproved and exercise guidelines have been altered and continue to be updated. There is now well documented research on the positive effects of exercise during pregnancy for several populations, healthy women, active women, previously sedentary women and women with high risk of maternal complications such as pre-eclampsia and gestational diabetes mellitus (GDM). It is in the best interest of health care providers, exercise physiologists and fitness trainers and mothers-to-be to become aware of the new guidelines for exercise during pregnancy.
The physiological changes that occur during pregnancy begin to take place immediately after conception. Adaptations occur throughout almost every body system, endocrine, respiratory, cardiovascular and musculoskeletal. Endocrine changes include the increase in concentration of estrogen, progesterone, cortisol, insulin and relaxin. Changes in the chest wall structure cause the respiratory system to increase ventilation, which is one reason many pregnant women feel short-of-breath during pregnancy. The biggest changes occur to the cardiovascular system. Blood volume increases by 40-50%, maternal heart rate and stroke volume increase, and the left ventricle of the heart itself grows slightly larger. Lastly, musculoskeletal changes include an increase in the inward curvature of the spine (lordosis), diastasis recti or abdominal separation, increased joint laxity, especially in the pelvis, and an overall shift in the center of gravity.
It is amazing how a woman’s body adapts during pregnancy to ensure proper health and protection to herself and her baby. These protective factors continue to work during pre-natal exercise. Now let me dispel some previous believed myths surrounding exercise and pregnancy.
These were the common myths once believed by health care providers and relayed to pregnant women:
Myth #1: Exercise will increase your body temperature and cause neural tube defects.
Fact: During moderate and high-intensity exercise core temperatures of pregnant women do not rise high enough to produce neural tube defects.
Myth #2: Decreased blood flow during exercise will compromise uterine blood flow and lead to fetal distress.
Fact: Uterine and placental blood flow is not affected by moderate intensity exercise.
Myth #3: The increase in glucose uptake during exercise will take away from the glucose needed for the fetus.
Fact: No association had been shown in differences in fetal growth when comparing exercising and nonexercising women. Women who exercise during pregnancy actually grow a larger placenta, which increases nutrient delivery to the fetus.
Myth #4: Exercising during pregnancy will cause preterm labor.
Fact: Studies have failed to demonstrate increased uterine activity during exercise. In fact, most studies on this subject have shown that exercising pregnant women are at a DECREASED risk for preterm delivery and that high-intensity exercise during pregnancy actually appears to reduce the risk of preterm birth.
The current guidelines set by the ACOG regarding exercise and pregnancy are as follows: Pregnant women, in the absence of either medical or obstetric complications, should get 30 min. or more of moderate exercise on most, if not all, days of the week. I cannot stress enough the importance of following these guidelines.
Now get out there and exercise!
Stay tuned for next month’s article on the benefits of exercise during and after pregnancy with some tips on how to stay motivated when you are feeling tired, sick, depressed or just plain BLAH!
**I am starting a new Mommy and Me class at Blend in April. Please check my website for more information on that class as well as my already ongoing pre-natal conditioning, labor preparation and meditation class.**
Kristen Miller received her Masters degree in Exercise Physiology from the University of New Mexico. She is a certified exercise physiologist and personal trainer with over twelve years of experience. Kristen’s focus is on preparing women for childbirth and beyond by strengthening the muscles used during labor and teaching women how to use them correctly. Kristen is currently offering a pre-natal class at Blend for Kids in Branford, CT. She also does private and small-group in home pre and post-natal conditioning and meditation. Please check the website for more information: www.ppnatalconditioning.com
