Pregnancy and physical activity

Baby, can you spare a climb?

General fatigue, exhaustion, and not wanting to harm one’s baby during pregnancy are the top reasons pregnant women abstain from regular physical activity. However, more and more scientific evidence documents physical activity’s positive role during pregnancy for both the mother and baby.

The figure below illustrates the prevalence and pattern of different activities during pregnancy among pregnant and nonpregnant women in the U.S. It might be surprising to some, but about 40 percent of women participate in different forms of physical activity during pregnancy.

Graph re: pregnancy/exercise

For both pregnant and nonpregnant women, walking represents the most common activity – 52 percent for pregnant women and 45 percent for nonpregnant women. Pregnant women who engaged in either moderate or vigorous physical activity are generally younger, non-Hispanic white, unmarried, and more educated. They also tend to be nonsmokers with higher incomes than their less physically active counterparts.

Physical activity effects on the mother

Conservative, prudent recommendations apply during a normal pregnancy, despite examples of extreme physical activity for well-trained women, without apparent negative effect on maternal or fetal health.

Thirty to 40 minutes of daily, moderate aerobic physical activity for a previously active, healthy, low-risk woman during an uncomplicated pregnancy does not compromise fetal oxygen supply or acid-base status, induce heart rate signs of fetal distress, or produce other adverse effects to mother or fetus. Performed on a regular basis, physical activity maintains cardiovascular fitness, promotes a training effect, and inhibits undesirable excessive weight gain for the mother.

The box (right) lists 2015 recommendations from the American College of Obstetricians and Gynecologistsregarding physical activity during pregnancy.

Maternal cardiovascular dynamics follow normal response patterns – moderate physical activity offers no greater physiologic stress to the mother other than the additional weight gain and possible encumbrance of fetal tissue. In fact, regular physical activity during pregnancy can reduce maternal weight gain by an average 6.8 pounds compared to women who do not exercise regularly.

Regular, moderate physical activity during the second and third trimesters reduces ventilatory demands and ratings of perceived fatigue. This training adaptation increases the mother’s ventilatory reserve and possibly inhibits exertional breathing problems sometimes seen during pregnancy.

Physical activity effects on the fetus

Contrary to belief, there is some long-term evidence that indicates physical activity during pregnancy does not increase risk of fetal deaths or low birth weights, but instead, may significantly reduce the risk of preterm births. In fact, a moderate program of walking, jogging, or recreational activity early in pregnancy through delivery enhances placental growth and reduces preeclampsia risk – a pregnancy complication characterized by high blood pressure and signs of damage to other organs, often the kidneys.

A recent study of women evaluated the effects of daily physical activity on timely delivery, and examined the safety and potential benefits of regular activity during pregnancy. Researchers looked at women who engaged in low-to-moderate activity: walking about about two miles per day, six days per week; more intense activity: walking greater than two miles per day, six days per week; and no physical activity. Results showed no association between low-to-moderate physical activity and gestation length. These data indicate that higher weekly physical activity volume lowers, rather than raises, risk of preterm birth.

Additional benefits of physical activity on newborns

Research shows that neonates born to mothers who regularly engage in physical activity during pregnancy exhibit a neurobehavioralprofile as early as the fifth day after birth, earlier than neonates from their more sedentary counterparts. Babies born to physically active pregnant women score higher in orientation behavior; they are more alert and interested in their surroundings, and less demanding of their mothers.

Also, babies of physically active pregnant women are lighter and leaner than offspring from nonphysical, active pregnant women. Continuing regular physical activity throughout pregnancy modifies neonatal behavior by positively affecting early neurodevelopment.

Physical activity guidelines during pregnancy

Always begin by warming up for five minutes and stretch for five minutes. Include at least 15-30 minutes of cardiovascular activity.

Follow aerobic activity with 5-10 minutes of gradually slower physical activity and end with gentle stretching.

Here are some basic guidelines for physical activity during pregnancy:

  • Wear loose-fitting, comfortable clothes as well as a good support bra.
  • Choose shoes with maximum support – proper shoes are the best protection against injury.
  • Exercise on a flat, level surface.
  • Consume enough calories to meet pregnancy needs (about 300 more calories per day than before pregnancy).
  • Finish eating at least one hour before activity.
  • Drink water before, during, and after activity.
  • Following floor exercises, get up slowly and gradually to prevent dizziness.
  • Never exercise to the point of exhaustion. If you cannot converse normally while exercising, you are probably overexerting yourself.
Stop activity and consult a health care provider if you experience the following:
  • Chest pain, abdominal pain, or persistent contractions
  • Feeling faint, dizzy, nauseous, lightheaded, cold, or clammy
  • An absence or decrease in fetal movement
  • Vaginal bleeding or sudden gush of fluid from the vagina or a trickle of fluid that leaks steadily
  • An irregular or rapid heartbeat
  • Sudden swelling of the ankles, hands, or face; pain in the calves
  • Shortness of breath
  • Difficulty walking
  • Muscle weakness
Avoid the following activities during pregnancy:
  • Holding the breath during any activity
  • Any activity in which falling is likely (skiing, horseback riding)
  • Any contact sport (softball, basketball, volleyball)
  • Activities that include jarring motions or rapid changes in direction
  • Activities that require extensive jumping, hopping, skipping, bouncing, or sprinting
  • Deep-kneee bends, full sit-ups, double leg raises, and straight toe touches
  • Bouncing while stretching
  • Waist-twisting movements while standing
  • Heavy activity spurts followed by long periods of inactivity
  • Physical activity in hot, humid weather

Postpartum physical activity

Beginning regular physical activity six-eight weeks postpartum produces no deleterious effect on volume or composition of lactation and improves aerobic fitness without impairing immune function. Fitness level and strength decline in the early postpartum period relative to prepregnancy performance, but generally return some 27 weeks after delivery. Combining moderate physical activity with a reduced energy intake of about 500 kcal daily allows overweight lactating women to safely lose 0.5 kg per week without adverse effects on infant growth.

Below are some simple exercise that can be performed during pregnancy.

Dancer’s Plie
Benefits: Strengthens quadriceps, hamstrings, and glutes; improves balance

  1. Dancer's plieStand parallel to back of a sturdy chair with the hand closest to the chair resting on the top, feet parallel and hip-distance apart
  2. With toes and knees turned out to 45 degrees, pull belly button up and in
  3. Bend knees, and lower torso as low as possible while keeping straight back
  4. Straighten legs to return to starting position
  5. Repeat for 10 reps

Side-lying inner and outer thigh
Benefits: Strengthens core and inner thighs

  1. Lie on right side, head supported by forearm, right leg bent at a 45-degree angle and left leg straight
  2. Place opposite arm on floor for stability
  3. Lift left leg to about hip height and repeat for 10 reps; then bend left knee and rest it on top of right leg
  4. Switch sides and repeat for 10 reps

Plank
Benefits: Strengthens core, arms, and back

  1. Get down on hands and knees, wrists directly under shoulders
  2. Lift knees and straighten your legs until body forms a straight line
  3. Don’t arch back or let belly sag
  4. Hold for 1-2 breaths, working up to 5 breaths
  5. Repeat for 10 reps

Seated curl and lift
Benefits: Strengthens biceps and shoulders

  1. Sit on the edge of a sturdy chair with back straight, feet on floor, arms at sides
  2. Hold a5-8-lb. weight in each hand, palms facing inward
  3. Bend elbows so arms form a 90-degree angle
  4. Keeping elbows bent, lift weights to shoulder height
  5. Lower arms to sides, then straighten to return to starting position
  6. Repeat for 10 reps

One-arm row
Benefits: Strengthens back, biceps, and triceps.

  1. Using a sturdy chair, place your right knee on the seat, left foot on the floor
  2. Bend forward, back parallel to floor, right hand on seat
  3. Hold a 5-8-lb. weight in left hand, arm extended down and in line with shoulder, palm facing in
  4. Bend left elbow up so arm forms a 90-degree angle
  5. Hold, and then return to starting position
  6. Repeat for 10 reps, and then switch sides

 
 
References

  • Barakat, R., et al. 2015. “Exercise during pregnancy. A narrative review asking: What do we know?” British Journal of Sports Medicine; 49(21):1377.
  • Daley, A.J., et al. 2015. “The effectiveness of exercise for the prevention and treatment of antenatal depression: Systematic review with meta-analysis.” British Journal of Obstetrics and Gynecology; 122(1):57.
  • Di Mascio, D., et al. 2016. “Exercise during pregnancy in normal-weight women and risk of preterm birth: A systematic review and meta-analysis of randomized controlled trials.” American Journal of Obstetrics and Gynecology; 215(5):561.
  • Elliott-Sale, K.J., et al. 2015. “Exercise interventions for weight management during pregnancy and up to one year postpartum among normal weight, overweight, and obese women: A systematic review and meta-analysis.” British Journal of Sports Medicine; 49(20):1336.
  • Hinman, S.K., et al. 2015. “Exercise in pregnancy: A clinical review.” Sports Health; 7(6):527.
  • McDonald, S.M., et al. 2016. “Does dose matter in reducing gestational weight gain in physical activity interventions? A systematic review of the literature.” Journal of Science and Medicine in Sport; 19(4):323.
  • Mottola, M.F., et al. 2016. “Fetal and maternal metabolic responses to exercise during pregnancy.” Early Human Development; 94:33.
  • Nascimento, S.L., et al. 2012. “Physical exercise during pregnancy: A systematic review.” Current Opinion in Obstetrics and Gynecology; 24(6):38.
  • Nascimento, S.L., et al. 2014. “The effect of physical exercise strategies on weight loss in postpartum women: A systematic review and meta-analysis.” International Journal of Obesity (London); 38(5):626.
  • Poyatos-León, R., et al. 2015. “Effects of exercise during pregnancy on mode of delivery: A meta-analysis.” Acta Obstetricia et Gynecologica Scandinavica; 94(10):1039. 

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