Pregnancy and Sports - Part 1
An increasing number of adolescent females are participating in recreational and competitive sports, strength training and other fitness activities. During pregnancy they may want to remain physically active and continue some of these activities. Other adolescents who were previously sedentary may want to begin an exercise program as part of a healthy lifestyle.
Safety of Exercise During Pregnancy
- Observational and interventional studies support the tolerance and safety of moderate exercise in healthy pregnant individuals.
- The fetus is protected from potentially harmful effects of maternal exercise (e.g., hyperthermia, decreased uterine blood flow and oxygen delivery, decreased carbohydrate availability and uterine contractions) by maternal physiologic adaptations to pregnancy.
- Exercise in normal (uncomplicated) pregnancies has not been associated with compromised fetal growth and development, premature labor or delivery complications.
- Mild to moderate exercise in pregnancy has been associated with a neutral or beneficial effect on pregnancy outcome.
- Healthy, well-nourished adolescents without obstetrical or medical complications can safely exercise with few restrictions during pregnancy.
- Adolescents who are trained athletes prior to pregnancy can continue to exercise throughout pregnancy with modifications made as needed.
- Adolescents who were not exercising regularly prior to becoming pregnant can safely begin an exercise program during pregnancy.
Potential Benefits of Exercise During Pregnancy
Physical exercise enhances muscular strength, endurance, flexibility and cardiovascular health. Additional benefits of exercise during pregnancy,1, 4-6 which may be especially important to the adolescent, are listed below.
- Fewer physical discomforts (e.g., fatigue, nausea, leg cramps, backache, constipation, round ligament pain, shortness of breath)
- Decreased incidence of operative delivery, gestational hypertension and preeclampsia
- Improved blood glucose control in gestational diabetes
- Shorter active phase of labor
- Improved self esteem and body image
- Decreased stress and anxiety and improved sleep
- Less isolation from nonpregnant peers
- Increased placental weight, blood flow and infant birthweight
- Maintenance or improvement of fitness level
- Less likelihood of excessive weight gain
- Fewer stretch marks
- Improved posture
- Faster postpartum recovery
Physiologic Considerations Affecting Exercise During Pregnancy
Physiologic changes associated with pregnancy may affect exercise tolerance and safety and must be considered when modifying or developing prenatal exercise programs.
- Beginning early in pregnancy, relaxin softens and stretches connective tissue, resulting in laxity and instability of ligaments and joints and increased risk of sprains and strains.
- The enlarging uterus and breasts and growing fetus shift the center of gravity, resulting in balance problems, increased lumbar lordosis (sway back), and greater strain on the lower back and hips.
- Weight gain may place additional stress on joints and make movement more difficult.
- In later pregnancy, edema may limit range of motion and cause nerve compression.
- Pressure exerted on the vena cava by the enlarging uterus may result in decreased cardiac output and reduced blood flow to the uterus when exercising on the back after the first trimester. Symptoms may include dizziness and shortness of breath.
- Hypoglycemia can occur more readily, especially in later gestation, or with prolonged, strenuous exercise, since carbohydrate utilization is greater in pregnancy.
- Increased resting oxygen consumption lowers oxygen availability for aerobic exercise in pregnancy.