7 Ways Exercise Benefits Pregnant Women and Their Babies

January 18th, 2010

After rereading my last post I realized it’s unfair of me to bash a study and not state my reasons why.  I came out strongly against the Madrid study which found that low resistance exercise in previously sedentary women didn’t affect the type of delivery that they had. Essentially these researchers took a a group of sedentary pregnant women with uncomplicated pregnancies, set them up with a very low intensity work out for the second and third trimesters of their pregnancies and then looked at modes of delivery.

moms2While the study seems to be carried out properly, my objections are that the women had not been adequately challenged, i.e. made to exercise with enough intensity, to be able to reap the benefits of prenatal exercise. As I mentioned in the last post, the exercise parameters that I use are those put forth by James Clapp, III, MD and Ann Cowlin, MA a Dance and Movement Therapist who have both done extensive research in exercise during pregnancy. They both advocate moderate intensity exercise 3-5 times a week for 20-30 minutes per session. By exercising at this frequency and intensity they both observed less maternal weight gain, lower incidences of gestational diabetes and hypertension, fewer aches and pains of pregnancy, shorter times in active labor (dilation from 4cm to 10 cm) , fewer interventions in delivery (i.e. forceps, vacuum, c-sections) a quicker return to pre-pregnancy weight.

But how exactly does moderate intensity exercise create these benefits? Let’s look at the effects of moderate intensity exercise on a pregnant woman’s anatomy and physiology. I promise not to get too geeky on you, just bear with me because this is important information.

Increased Muscle Tone

Just as in the non-pregnant state, exercise that includes strength training exercises maintain and/or increase endurance and muscle tone, creating more stamina, lean muscle and less body fat. For a pregnant mama, this means increased metabolism (muscle burns more calories than fat) and increased energy to perform the her activities of daily life. Most mamas who have engaged in regular, moderate exercise during pregnancy experience fewer of the common aches and pains of pregnancy, have shortened durations of active labor and subsequently need fewer pushes to deliver their babies. Post partum, they return to their pre-pregnancy weights sooner.

Increased Skeletal Stabilization

This goes hand in hand with increased endurance and muscle tone. A mama with well toned muscles will have more stability in her frame. Strength training enables Mamas to have better posture; a straighter back, less rounded shoulders and less neck strain. More skeletal stabilization leads to more hip and pelvic stability and less pain. Overall Mama will be less uncomfortable as her pregnancy progresses.

Improved Metabolism

Just as in the non-pregnant state, exercise increases metabolism by increasing the number of energy centers within muscles to utilize the nutrients we eat to create energy. Food mama eats will be used more fully for energy and development of her baby and less will  be stored as fat. As a result,  mama will be less likely to develop gestational diabetes or high blood pressure (hypertension).

Improved Circulation

Mamas who exercise also increase their blood circulation despite the increase in overall body fluid volume. Blood and body fluids are well circulated and don’t readily pool leading to swelling and increased of blood clot formation.  For pregnant mamas who exercise, this means less swelling in the hands and feet and a lower risk of developing a blood clot in one of her legs that could dislodge and travel to her heart, lungs or brain and be potentially fatal.

Better Sleep

Ever notice that you sleep better when you exercise regularly? Well, exercising during pregnancy has the same effect. Some women note difficulty sleeping while pregnant.  If this is the case, try adding a brisk daily walk or some strength training to your daily routine and see if you are able to get a better night’s sleep.

Improved Placental Growth and Functional Capacity

This was an unexpected finding that Dr. Clapp found in his research. Prior to Dr. Clapp’s research obstetricians and researchers believed that exercising during pregnancy would somehow impair the growth and development of the placenta. Dr. Clapp and his associates, using a special ultrasound machine, measured placental growth in his study subjects. Dr Clapp found that exercise didn’t stunt growth of the placenta, it actually increased its growth rate during the mid portion of pregnancy. Additionally, these larger placentas had more functional capacity, i.e. increased ability to nourish the babies, because they had more blood vessel development. This was a fantastic finding because at the end of pregnancy, when babies are growing rapidly, the larger, more vascular placenta is able to deliver more nutrients to the baby.

“Lean Mean Babies”

After establishing that exercise is good for mothers, Clapp set out to see what effect moderate exercise had on the growing babies. Clapp found that babies born to mothers who exercise are not at risk of being of low birth weight. They may weigh less than babies born to non-exercising mothers, but they are still of normal, acceptable birth weights and sizes. These babies also had less body fat than their counterparts. (Remember, they were being well fed by a highly functional placenta!) These babies also adapt well to stimuli and if there are complications during labor and delivery, they are better able to adapt and compensate giving clinicians a bit more time to assist if necessary.

This research has significant implications for women who exercise during pregnancy. But what happens if a woman stops exercising late in her pregnancy? Clapp found that women who stopped exercising late in pregnancy, say at 32 weeks lost all the benefits they had developed. They began gaining weight, experiencing the aches and pains of pregnancy,  swelling in their hands and feet and they tended to have larger babies.

If women are going to exercise during pregnancy, they need to exercise at a moderate intensity (12-14 out of 20 on Borg’s Scale of Perceived Exertion) 3-5 times a week for 20-30 minutes and, as much as possible, they should continue exercising as close to delivery as possible.

Do you exercise or did you exercise while you were pregnant? Share your experience in the comment section below.

Mamas on bed rest, you may not be able to engage in cardiovascular exercise, but you can strength train using exercise bands. A simple, yet effective set of exercises is waiting for you in Bedrest Fitness. Even if you are unable to do all of the exercises, your body will appreciate the movement. Get your copy of Bedrest Fitness Here

2 responses to “7 Ways Exercise Benefits Pregnant Women and Their Babies”

  1. This post was nicely done. I remember reading somewhere when I was pregnant 15 yrs ago that any exercise done regularly prior to pregnancy could be safely continued in a low-risk pregnancy, just modified for the growing belly and not to the point of exhaustion.
    Of course, high-risk mommas and those on bedrest should double check with their care-providers prior to engaging in any exercise routine, and low-risk mommas might feel better getting clearance from their providers as well.

  2. Darline says:

    Before I work with any pregnant woman I require her to have a signed waiver from her obstetrician or midwife.
    Those women who purchase Bedrest Fitness, the exercise DVD for pregnant women on bed rest are advised to
    also get clearance from their obstetricians or midwives. Thanks for this reminder!

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