EXERCISE DURING PREGNANCY
Currently, the benefits of exercise are well-known. Regular exercise helps control weight, reduce the risk of cardiovascular disease, reduce the risk for type 2 diabetes and metabolic syndrome, reduce the risk of certain cancers, strengthen bones and muscles, improve mental health and mood, and increases healthy lifespan (Physical Activity and Health, 2015). Although changes occur during pregnancy, current research supports regular activity throughout a pregnancy so long as no other health conditions say otherwise. Prior to 2002, recommendations limited women to walking one mile a day or 15 minutes of aerobic exercise with a maximum heart rate of 140 beats per minute (Freyder, 1989; Paisley, Joy, & Price, 2003). In 2002, a formal recommendation from the American College of Obstetrics and Gynecology (ACOG) stated, “in the absence of either medical or obstetric complications, 30 minutes or more of moderate exercise a day on most, if not all, days of the week is recommended for pregnant women” (Paisley et al., 2003).
Regular participation in exercise not only allows pregnant women to continue to reap the benefits that all individuals find with regular exercise, but exercise may also improve the pregnancy experience (Freyder, 1989; Paisley et al., 2003). Strength training may decrease discomfort and offset postural changes during pregnancy, women may experience improved self-image, and the duration of labor, rate of Cesarean secretion and the length of hospital stay may decrease for women participating in regular exercise (Freyder, 1989; Paisley et al., 2003). In addition, many women participating in regular exercise experience reduced “fatigue, varicosities, and swelling of the extremities…less insomnia, stress, anxiety, and depression” (Paisley et al., 2003). Plasma glucose levels were reduced with 45 minutes of exercise, reducing the risk for gestational diabetes (Paisley et al., 2003). Furthermore, “women who incorporate exercise into their routine during pregnancy are more likely to continue exercising postpartum” (Paisley et al., 2003), which improves health outcomes after the pregnancy.
While exercise is strongly recommended for women during pregnancy, it is important to acknowledge the physiological changes that occur during pregnancy so that one can monitor her health. Normal cardiovascular and respiratory changes, energy expenditure, increased body fluid, and changes in posture, gravity and body weight should be considered (Freyder, 1989; Paisley et al., 2003). Cardiac output can increase up to 50%, resting heart rate typically increases 15 beats per minute, and blood volume increases 45%. Minute ventilation increases 50%, tidal volume increases, resting oxygen requirements increase, and the work of breathing increases. Endocrine and metabolic changes alter the energy expenditure, and required energy intake increases by approximately 300 kilocalories a day. Increased body fluid during pregnancy make it that much more important to stay hydrated during exercise. Finally, the weight gain of 20-40 lbs. that occurs during pregnancy alters posture and center of gravity and can impact the joints. Regular exercise may improve the ability to adapt to these changes during pregnancy.
While regular exercise is recommended for all women during pregnancy as long as there are no other health complications, the prescription for intensity and duration may vary. One should assess her current fitness status and activity level and reflect on her individual goals for exercise (Paisley et al., 2003). If classified as a sedentary pregnant women, exercise prescription should be moderate, low-impact activity for 30 minutes, 3 times per week. A recreational athlete should include moderately hard to hard activity for 30-60 minutes, 3-5 days per week. An elite athlete should exercise at a hard intensity level including competitive activities for 60-90 minutes, 4-6 days per week. The prescription is important to discuss with a health professional in order to avoid any adverse effects to exercise during pregnancy.
It is apparent that exercise is beneficial for the majority of pregnant women. However, there are “absolute and relative contraindications to aerobic exercise during pregnancy” (Paisley et al., 2003). Absolute contraindications include hemodynamically significant heart disease, restrictive lung disease, incompetent cervix/cerclage, multiple gestation at risk for premature labor, persistant 2nd or 3rd trimester bleeding, placenta previa after 26 weeks gestation, premature labor during the current pregnancy, ruptured membranes, and pre-clampsia/pregnancy-induced hypertension (Paisley et al., 2003). Relative contraindications include severe anemia, unevaluated maternal cardiac arrhythmia, chronic bronchitis, poorly controlled type I diabetes, morbid obesity, extremely underweight, history of extremely sedentary lifestyle, intrauterine growth restriction in current pregnancy, poorly controlled hypertension, orthopedic limitations, poorly controlled seizure disorder, poorly controlled hypothyroidism, and heavy smoking (Paisley et al., 2003). These conditions should be screened for at a prenatal evaluation. Warning signs to stop exercise during pregnancy include vaginal bleeding, dyspnea prior to exertion, headaches, dizziness, chestpain, muscle weakness, calf pain or swelling, preterm labor, decreased fetal movement, or amniotic fluid leakage (Paisley et al., 2003).
Women should be encouraged to exercise while pregnant while remaining aware of the changes that are normal and those that are not (Freyder, 1989; Paisley et al., 2003). Physicians may play an important role in identifying optimal intensity, duration, and frequency of exercise routines for women during pregnancy (Paisley et al., 2003). The health benefits that occur in women participating in exercise during and after pregnancy are seen in physical and psychological responses to activity, and are important for long-term health. So, start setting a good example of healthy habits for your child during the pregnancy with a regular exercise routine!
Physical Activity and Health. (2015, June 4). Retrieved from https://www.cdc.gov/physicalactivity/basics/pa-health/
Freyder, S.C. (1989, March). Exercising while pregnant. The Journal of Orthopaedic and Spots Physical Therapy, 358-365. http://www.jospt.org/doi/pdf/10.2519/jospt.19220.127.116.118
Paisley, T.S., Joy, E.A., Price, Jr., R.J. (2003). Exercise during pregnancy: A practical approach. Current Sports Medicine Reports, 2, 325-330. https://www.researchgate.net/profile/Elizabeth_Joy2/publication/9036694_Exercise_during_pregnancy_A_practical_approach/links/54a720030cf257a6360ab884.pdf