August 1, 2007

Having a Baby Changes Everything: Staying Fit During Pregnancy

No one can forget the day they find out they’re pregnant. It’s a joyous moment, even after you throw up. From that moment on and for the next 40 weeks you are constantly reminded that your body is no longer your own. Your lifestyle, diet, and exercise must now take into account your developing baby.

The decision to continue exercising may not be yours to make. Previous health history may lead your physician to advise against it or, like me, you may simply be too sick to even contemplate getting off the couch.

Then there are those who feel fantastic during pregnancy.

Fitness model Francisca Dennis says she loved being pregnant, which is why she has six kids, and continued with a four-days-a-week cardio program plus three full-body workouts. Fitness champion Kary Odiatu continued with weight and cardiovascular training and pre-natal yoga during her first pregnancy, and took a pre- and postnatal certification. Figure pro Dionne Sinclair also found that pregnancy didn’t slow her down. She carried on her normal life, working full-time and going to the gym three times a week right until delivery.

Stay active

There is no debate – pregnant women benefit from exercise. Studies have concluded that women in shape not only feel better but actually have easier, shorter labors and deliveries. That in itself should compel anyone into the gym!

Exercise can also alleviate many of the annoying aches and pains associated with pregnancy. Back and joint pain occur less with active pregnant women and exercise reduces the constipation and normal anxiety that sometimes occur. However, within the medical community, there are concerns over the safety of some types of exercise.

Aside from the obvious fact that a pregnant woman should avoid any exercise or sport that puts her at risk for physical trauma, there are five main concerns that arise from the physiological changes in a pregnant woman’s body.

1. Inadequate caloric intake

• Eat more.

Exercise alone increases your appetite; couple that with a developing baby, and pregnant women must ensure that they are meeting their body’s increased energy demands by eating enough.

It is not known exactly how much more an active pregnant woman must eat, but here is an idea: A developing baby alone requires an additional 150 calories per day during the first two semesters and 300 calories per day during the third. Now add these calories to those just burned in the gym, and you may get a sense of how much more food should be eaten.

It is theorized that if not enough calories are consumed, the exercise demands of the mother outweigh those of the baby and may affect its development. This is just a theory and no research has demonstrated that exercise, especially during the first and second trimester, negatively impacted fetal weight. Only when the mother exercised into the third trimester was fetal weight gain very slightly diminished, yet it was still within normal limits.

2. Increased body temperature

• Avoid exercise in hot or humid weather.
• Drink plenty of water.

Pregnant moms are cautioned against hot tubs and hot baths, since heating the body to over 39.2 °C (102.6 °F) – especially during the first trimester – has been associated with an increase in birth defects.

The developing fetus creates quite a bit of heat. Fetal temperatures are one-half to a full degree higher than the mother. To compensate, a mother’s body increases skin blood flow causing her body temperature to decrease 0.1 °C per week throughout her pregnancy.

Exercise by itself does not significantly raise a pregnant women’s core body temperature, but exercise coupled with extreme temperatures may, which is why pregnant women are cautioned against exercise on very hot days or going to exercise classes with overheated rooms.

Keeping cool also means keeping hydrated during exercise. It is surprising how much water is lost in perspiration. A pregnant woman should drink four cups of water per hour of activity – one cup every 15 minutes. Afterwards, more water should be drunk, for it is possible to lose up to eight cups of water in perspiration in just one hour of exercise.

3. Breathing difficulties

• Always be able to talk during exercise, never exercise to the point of breathlessness.

Pregnant women will notice that during exercise they breathe more heavily. Not only are there additional oxygen requirements for the developing baby, but it is also pushing up against the diaphragm, making deep breathing difficult. Heavy cardio work should be avoided.

4. Blood flow (hemodynamics)

• Avoid exercise that involves lying flat on your back, especially during the last two trimesters.

Since exercise drives blood into muscles, taking it away from other organs, including the uterus, it is theorized that perhaps this shunting of blood occurring during pregnancy may be harmful to the baby. All studies surrounding this are inconclusive and, as well, fetal heart rate appears unaffected while a mother is exercising. These results are explained by the fact that pregnant women have increased blood volume and heart rate, ensuring there is always enough blood reaching the fetus.

The second issue of blood flow is exercise position. When lying on your back, the developing baby pushes against the cardiovascular system, decreasing blood flow. Pregnant women are cautioned to exercise on their sides during the final trimester.

5. Muscoluskeletal changes

• Avoid fast movements during exercise.
• Avoid unstable ground when running or cycling.

Though it’s hard to believe during labor, throughout your pregnancy hormones are released which relax hip joints in order to facilitate delivery. It is thought that other joints loosen as well, and even while studies have found increased joint flexibility, none has found an increased rate of injuries with pregnant women.

This being said, pregnant women do become less agile because of a shift in their center of gravity. This is the result of the increased weight of breasts, uterus, and baby. Any exercise that would compromise a pregnant woman’s balance – such as tennis or squash – should be avoided because of the increased chance of falling.

Furthermore, the overall weight gain from a pregnancy can lead to uncomfortable back strain and increased discomfort with weight-bearing exercises such as running.

When to quit

If you are pregnant and exercising, stop immediately if you feel any of the below five symptoms:

1. Pain in your back or pelvis
2. Racing heart
3. Shortness of breath
4. Dizziness
5. Fatigue

Conclusion

• Be prudent.
• Listen to your body.

For obvious reasons, studies on the effects exercise has on pregnant women and their babies are limited. Therefore, the medical community is very cautious and conservative in its recommendations for what constitutes a safe level of exercise. It is a personal decision that should be made in conjuncture with your doctor.

That being said, the American College of Obstetricians and Gynecologists states: "If you are active now, pregnancy need not cause you to alter your fitness routine. If you have not been active, now is a good time to start."

Safe exercising guidelines are available from the American College of Obstetricians and Gynecologists (www.acog.org) and the Royal College of Obstetricians and Gynecologists. (www.rcog.org.uk/index.asp?PageID=1366).

...Alison Aulph
alison@seriousaboutfitness.com

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