Pregnancy and Sports - Part 2
Guidelines for Exercise During Pregnancy
- Prenatal exercise programs must be individualized according to the adolescent’s health status, interests and fitness level. Desirable components include aerobic conditioning, strength training and flexibility exercises.
- Regular exercise (at least three times per week) is preferable to intermittent activity or a sudden increase in exercise level, which can result in muscle strain.
- Exercise sessions should begin with a warm-up and end with a cool-down and relaxation period (e.g., 10-15 minutes of slow walking or stationary cycling on low resistance followed by gentle stretching). This will reduce the risk of ligament and back strain, ensure a safe cardiovascular response, normalize metabolic rate and respiration and prevent pooling of blood in exercising muscles. After exercise, the adolescent should rise gradually from the floor to prevent dizziness.
- Exercises that require lying on the back should be avoided after the first trimester.
- Exercise intensity should be light enough to allow conversation and prevent shortness of breath, fatigue, pain, and exhaustion. Since resting heart rate increases and maximum heart rate decreases in pregnancy, monitoring target heart rate to determine exercise intensity is of limited usefulness.
- Fatigue and discomfort may be less likely if exercise intensity is decreased in later pregnancy (e.g., exercising more slowly with fewer repetitions, or engaging in less strenuous activities such as doubles tennis instead of singles, walking instead of running).
- Exercise sessions should be short enough to prevent hypoglycemia, fatigue and discomfort (e.g., 20-30 minutes of moderate aerobic activity, 3-5 times per week).
- Running may require shorter distances, slower speeds, flatter terrain and more frequent rest periods.
- Strength training should be limited to 2-3 times per week using light weights (2-5 kg) and fewer repetitions. Heavy free weights or heavy resistance on weight machines could increase the risk of spinal disc injury and intra-abdominal pressure. Straining and breath-holding should be avoided.
- Exercise activities that do not require a high degree of balance and coordination, quick movements, or involve the risk of falling or fetal trauma are considered safe during pregnancy.
- The pelvic tilt will help strengthen abdominal muscles, and decrease round ligament pain and lumbar lordosis. Instruct the adolescent to stand, lie or sit with feet hip-distance apart and knees slightly bent, while the muscles of the abdomen and buttocks are contracted. The pelvis is thrust forward and the pelvic bone is rolled upward.
- Exercises which strain the lower back, stress ligaments, cause knee trauma or promote separation of the of the symphysis pubis (junction of pubic bone) should be avoided. These include full sit-ups, sitting cross-legged, double leg lifts, side leg swings, toe touches, squatting, deep knee bends and bridging (lifting buttocks off floor from lying position).
- Jerking motions, hopping, jumping, twisting or sudden changes in direction are contraindicated. Joints should not be extended beyond the normal range of motion.
- Water skiing could result in forceful entry of water into the uterus, which could result in miscarriage.
- Scuba-diving may be associated with decompression disease, gas embolism, and in the first trimester, risk of fetal malformation.
Examples of Activities Considered Safe During Pregnancy
Walking, Rowing, Power walking, Dancing, Jogging, Prenatal exercise classes, Running, Cross country skiing, Swimming, Snorkeling, Water aerobics, Tennis, Water jogging, Bowling, Low impact aerobics, Golfing, Stationary cycling, Light weight training
Exercise Environment
- Particularly during the first trimester, overheating (which may have teratogenic effects on the fetus) should be avoided. Exercise should not be done while febrile or in hot, humid weather. Saunas or hot tubs may also increase the risk of hyperthermia and should be avoided. Exercising in light clothing during a cooler time of day outdoors, or with a fan indoors will help prevent dehydration and hyperthermia in hot weather.
- A tightly carpeted or wooden floor will reduce the risk of slipping.
- Walking or running on a cushioned track or grass will increase comfort and reduce the risk of injury.
- Well-cushioned shoes that provide good support will aid balance and increase comfort.
Nutrition Guidelines
- Ample fluid intake is essential to prevent dehydration, which occurs more readily in pregnancy (10-12 cups per day, including 2 cups before exercise, 1 cup every 15 minutes during, and 2-3 cups after exercise). Thirst may be depressed during exercise and cannot be relied upon to assure an adequate fluid intake. Clear, light-colored urine is an indicator of adequate hydration.
- An increased intake of carbohydrate will reduce the risk of hypoglycemia. Complex carbohydrates (e.g., bread, pasta, cereal) or milk, fruit or fruit juice should be consumed 1-2 hours before, and within 1 hour after exercise.
- Energy intake should be adequate to support exercise and promote optimal weight gain and fetal growth. Weight loss should not occur with exercise during pregnancy. The energy required for weight-bearing exercise (e.g., walking, running) increases with gestational weight gain.