Women’s Fitness & Health Issues

Pregnant Women Should Not Skydive

By: Dennis M. Loya, BS.,JD., Certified Personal Trainer


It goes without saying that every pregnant woman must cut back on exercise during her pregnancy to avoid harming herself or her baby. This begs the question, how should I modify my exercise routine to accommodate my pregnancy?

Pregnancy is a complex physiologic state, and precautions are needed during pregnancy to ensure that your exercise program does not contribute to complications.


Women who exercise moderately while pregnant are positively impacting the growth of their babies, according to the results of a recent study in the American Journal of Obstetrics and Gynecology. The study concluded that the babies born to exercising mothers were both larger and heavier than those born to the sedentary mothers.

The benefits of continuing exercise during pregnancy are many, though some doctors are reluctant to recommend starting an exercise program during pregnancy if the woman was previously inactive. “Nevertheless,” writes lead researcher Dr. James Clapp and colleagues, “an early introduction of a moderate-intensity regimen of weight-bearing exercise during pregnancy may have preventative value in individuals or populations at risk of having low birth weight babies.”

According to recent research published in the American Journal of Obstetrics and Gynecology that studied the effects of exercise during pregnancy, the amount and intensity of exercise can affect both maternal and fetal weight.

Seventy-five moms who already exercised regularly five times a week were assigned to one of three exercise groups. One third of the moms initially did 20 minutes of aerobic exercise and increased the duration of the exercise session over the course of their pregnancies; one third of the moms initially did 60 minutes and then decreased the duration of their exercise sessions; and one third of the moms exercised for 40 minutes throughout the entire pregnancy.

The results? The babies of moms who worked out intensely in mid- or late pregnancy were significantly lighter and had less body fat than infants born to the moderate exercisers. However, these lighter infants weren’t small enough to be at risk for medical or developmental problems. In addition working out regularly during pregnancy controlled the mother’s weight in some cases – women who exercised vigorously during early pregnancy and then reduced the amount of exercise as pregnancy progressed weighed more and had heavier placentas than women in the other groups. Exercise during pregnancy can be beneficial for babies and moms, and can help moms control weight gain during pregnancy.

A study published in the “American Journal of Obstetrics and Gynecology” showed that just five days after birth, infants whose mothers ran, did aerobics or swam throughout pregnancy were more alert and less fussy than babies whose moms took it easy.

To see whether regular workouts during pregnancy altered newborns’ behavior, Dr. James Clapp and colleagues at MetroHealth Medical Center in Cleveland compared infants born to 34 women who exercised, with those of 31 who did not. They tested each baby in seven types of behavior and found that those in the exercise group performed significantly better on two of the tests.

Active moms’ babies were more alert and interested in their surroundings, and these babies were also less cranky and demanding of their mothers’ attention, compared with the other infants. On the other five measurements, both groups of infants performed similarly.


There is no data that pregnant women should limit their exercise intensity or target heart rate because of potential adverse effects. For women who do not have any additional risk factors for adverse maternal or perinatal outcome, the following recommendations may be made:

1. During pregnancy, women can continue to exercise and derive health benefits even from mild to moderate exercise. Regular exercise (at least 3 times per week) is preferable to intermittent activity.

2. Women should avoid exercise in the supine position after the first trimester. Such a position is associated with decreased cardiac output in most pregnant women. Because the remaining cardiac output will be preferentially distributed away from the uterus during vigorous exercise, such regimens are best avoided during pregnancy.

3. Women should be aware of the decreased oxygen available for aerobic exercise during pregnancy. They should be encouraged to modify the intensity of their exercise according to maternal symptoms. Pregnant women should stop exercising when fatigued and not exercise to exhaustion. Weight bearing exercises may under some circumstances be continued at intensities similar to those prior to pregnancy throughout pregnancy. Non-weight-bearing exercises such as cycling or swimming can be substituted to minimize the risk of injury and facilitate the continuation of exercise during pregnancy.

4. Morphological changes in pregnancy should serve as a relative contraindication to types of exercise in which loss of balance could be detrimental to maternal or fetal well-being, especially in the third trimester. Further, any type of exercise involving the potential for even mild abdominal trauma (such as horseback riding, sky diving, skiing, and bike riding on wet or uneven surfaces) should be avoided.

5. Pregnancy requires an additional 300 kcal/day in order to maintain metabolic homeostasis. Thus, women who exercise during pregnancy should be particularly careful to ensure an adequate diet.

6. Pregnant women who exercise in the first trimester should augment heat dissipation by ensuring adequate hydration, appropriate clothing, and optimal environmental surroundings during exercise.

7. Many of the physiological and morphological changes of pregnancy persist for 4 to 6 weeks postpartum. Thus, pre-pregnancy exercise routines should be gradually resumed, based on a woman’s physical capability.

The best exercises for women are walking jogging, swimming, stationary cycling, and tennis, are all considered good, safe exercise during pregnancy, as long as you do not overdo it.


One of the best cardiovascular exercises for pregnant women, walking keeps you fit without jarring your knees and ankles. It’s also a safe activity throughout the nine months of pregnancy and one of the easier ways to start exercising if you are not a regular exerciser.

If you’ve been walking, keep it up. If you were fairly inactive before you became pregnant, start with a slow walk and build yourself up to brisk 20- to 30-minute jaunts. You could alternate a few minutes at a brisk pace with a few minutes at a slower pace. It’s best to exercise at least three times a week. Working out infrequently can put you at risk of injury; plus, you don’t benefit from exercise by working out only once in a while.


Swimming improves circulation, increases muscle tone and strength, and builds endurance. But the reason swimming is one of the better exercises it makes you feel almost weightless, and it is almost impossible to hurt yourself or your baby.

Before you take the plunge, check first with your doctor. If you were an avid swimmer before you got pregnant, you should be able to continue your usual regime. Even if this is all new to you, you will still be able to take to the water as long as you’re careful.

Start slowly, warm up and cool down gradually, and don’t over-exert yourself or exercise too hard. Just remember: all you want to do is stay fit, so take it easy and save the gruelling multi-lap workouts for the dreaded after birth. Choose a stroke which feels comfortable for you. Alternating breaststroke with floating on your back and gently kicking your legs will give you a good all-round workout. Avoid breaststroke if you have pain in your pubic area at the front of your pelvis.


Women who bicycle should ride a flat course during their first trimester and switch to a stationery bicycle during the second and third trimester due to the potential risks of falling and causing injury to the fetus.


* If strength training is part of your routine heavy-resistance machines are not appropriate for most pregnant women. It is recommended that exercise be decreased to a level of exertion by up to 30 percent.

* Abdominal exercises should be continued throughout pregnancy as they can help make pushing the baby out of the womb easier as well as help with low back pain. However, they should not be performed on the back after the first trimester.

* Avoid holding the breath (known as the Valsalva maneuver).

* Avoid prone (lying on stomach) and supine (lying on back) exercises after the first trimester.

* It may be best to decrease the weights slightly and increase the rest periods

between exercises as pregnancy progresses.

* Maintain proper posture while exercising.


Sports with a high potential for hard falls or ones where you might be thrown off-balance are not a good idea for pregnant women. These include horseback riding, skydiving and waterskiing. Additionally, most doctors recommend giving up bicycling after the second trimester, even if you’re an experienced cyclist, because of the potential for falls, however, as stated previously after the first trimester it would be safe to switch to a stationary bicycle.

Some women experience preterm contractions throughout their pregnancy. Preterm contractions do not always lead to preterm birth, they do increase a women’s risk of preterm labor significantly. If there are frequent contractions during pregnancy, strenuous exercise may lead to a higher rate of contractions. Exercise programs should be adjusted to include more non-weight bearing exercise like yoga, stretching and swimming. This goes without saying but it must be said that contact sports are best avoided after early pregnancy, and you should avoid activities with a high risk of falling from a great height (sky diving). Usually the fetus is well protected from bumps and falls, but a freak accident could still be dangerous.

In pregnancy the respiratory rate is naturally increased. Because of this, the body works harder to give enough oxygen to the developing fetus. This can reduce the amount of oxygen available for exercise and can cause decreased endurance and a sense of breathlessness.

Because of the enlarging womb, the lower back develops more curvature and the center of gravity for your body shifts. This can cause changes in your sense of balance and requires adjustments in posture to prevent injury. Usually women find that they naturally alter their exercise program to accommodate these changes, especially in the second and last trimester of pregnancy.

A woman’s joints also undergo changes during her pregnancy. Her body releases a hormone called “relaxin” which loosens up the joints of the pelvis to make room for the birth of her child. Because all of the joints in the body are more at ease, there is a greater chance of spraining or straining muscles and joints during pregnancy.

During pregnancy a woman’s body uses carbohydrates more quickly. Exercise also increases the metabolism of carbohydrates. These two factors can lead to low blood sugar reactions during exercise. Increasing caloric intake to shift her carbohydrate balance is very important for pregnant athletes.

Her body increases its blood volume by 40% in pregnancy and her heart rate increases by about 15 beats per minute. This allows nutrients and oxygen to be transported to the fetus more efficiently. However, with the growth of the womb, the flow of blood in the body can be disrupted and lightheadedness can occur.

The pelvic floor is formed of layers of muscle, which support the uterus, bowel and bladder. Pregnancy and childbirth puts pressure on the muscles, and as a result, may find leaking urine during a sneeze or cough this is called “stress incontinence”. Toning the muscles so they maintain or retrieve their strength and supportiveness is done by doing several Kagels – several times a day if possible.

Remember, during your pregnancy you should gain between ¾ and one pound per week after the first trimester. If you are underweight your doctor may counsel you to put on more than the average 35 pounds and if you are overweight your doctor may counsel you to put on less than 35 pounds.


The benefits of exercise during pregnancy include the following:

Exercise may boost energy levels, increase maternal self-esteem, decrease the risk of excessive weight gain, decrease the likelihood of varicose veins, hemorrhoids, pregnancy induced diabetes, and low back pain. In addition, exercise helps prepare the body for the stresses of labor and delivery. Research shows that women who exercise during pregnancy have fewer complications of labor and delivery. Recent research even indicates that vigorous (but not low intensity) exercise encourages on-time deliveries.

Disclaimer–No warranty is given as to the accuracy of the information on any of the pages in this article. No responsibility is accepted for any loss or damage suffered as a result of the use of that information or reliance on it. It is a matter for users to satisfy themselves as to their medical and physical condition to adopt the information or recommendations made. Notwithstanding a users medical or physical condition, no responsibility or liability is accepted for any loss or damage suffered by any person as a result of adopting the information or recommendations.

Copyright © 2003 by Dennis M. Loya, JD.

All rights reserved. Except for use in a review, the reproduction or utilization of this work in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including xerography, photocopying, and recording, and in any information storage and retrieval system, is forbidden without the written permission of the author. Author Biography

Dennis M. Loya, JD. is owner of IronWerks™, a personal training service that focuses on weight loss, nutrition, sport specific and condition specific training serving the beautiful Newport Beach/Corona Del Mar area of Southern California. Dennis has a law degree from American College of Law, and is a Certified Personal Trainer through the International Fitness Professionals Association (IFPA) and National Personal Training Institute (NPTI) and is a AMFPT and NPTI Certified Sports Nutritionist. Dennis has been involved in training and health related issues for over 25 years. As a trainer, he specializes in physique transformation, exercise for pregnant women, and sport-specific strength training preparation. IronWerks™ web site can be found at http://www.fitnessresultsnow.com/ the phone number is 949.278.3875 and any correspondence can be sent to:

IronWerks™ Personal Training
Attn.: Dennis Loya
1000 W. MacArthur Blvd. #21
Santa Ana, CA 92707

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