There are many benefits to exercising during pregnancy; these benefits last throughout the duration of the pregnancy, the labor and delivery, and the recovery period. Pre-natal activity leads to improved muscular strength and endurance, increased cardiovascular fitness, better posture, and an improvement in circulation, energy levels, and self-esteem. Additionally, exercise can decrease or prevent constipation, leg cramps, insomnia, fatigue, back pain, anxiety, depression, varicose veins, and extremity swelling. Research also shows that women who exercise through the full term have shorter labors and easier deliveries. After delivery, studies show that fit women recover faster than unfit women and return to normal activities 40% faster.
Healthy women who do not have complications do not need to limit their exercise routines. There is no data to suggest that pregnant women should limit exercise intensity and lower target heart rate. ACSM only recommends that women continue their pre-pregnancy exercise routine, but not increase the intensity. However, there are certain medical conditions which are contraindicated to exercise, and pregnant women should be evaluated and obtain permission from their physician before a trainer begins to work with them or before they start any kind of cardiovascular program. Additionally, pregnant women should avoid any type of exercise that may have a potential for impact or that has a high degree of balance or agility needed, such as ice skating, horseback riding, or skiing.
One of the concerns about women exercising during pregnancy had been that the fetus was at risk from overheating. Under normal resting conditions, the fetal temperature is 1 degree higher than the mother’s. Current research does not show that the fetus is at risk from women who exercise vigorously early in their pregnancy. Actually, it seems that the pregnant woman’s body adapts to regulate their body temperature and dissipate heat. Pregnant women should still stay well hydrated, wear loose fitting and lightweight clothing and avoid exercising in hot and humid conditions.
While exercising, women should gauge their intensity by using RPE (rating of perceived exertion), which should be between a 5-8 on a scale of 1-10. If exercise results in increased fatigue, then intensity and/or duration should be decreased. Modify exercises that feel awkward or uncomfortable, and report any unusual discomfort or symptoms to your trainer. Focus on posture and maintain good alignment.
Pregnant women can safely perform resistance exercise, but heavy weightlifting that requires straining should be limited. It is also important to avoid lying on your back during the second and third trimesters of pregnancy. This is because the extra weight of the enlarged uterus may compress the vena cava, which is the main blood vessel, which returns blood to the heart. If blood flow is restricted, blood pressure and fetal blood supply and oxygen may be decreased, which may affect fetal growth and development.
In addition to a regular exercise routine, pregnant women should do pelvic floor exercises, called kegels. Kegels are a very important exercise for pregnant women because they strengthen and protect the pelvic floor muscles. They help decrease urinary stress incontinence both pre and post partum. Strong muscles also prevent pelvic organ prolapse, pelvic pain, and misalignment of some joints in the hip area. It also helps with the pushing phase of labor.
Diet is also extremely important during pregnancy. Pregnant women need to eat a healthy balanced diet with plenty of fruits, vegetables, lean meats, and complex carbohydrates. It is best to eat small frequent meals and drink fluids regularly to avoid dehydration, decreased blood sugar, and to ensure adequate nutrients. They should eat a pre-exercise snack and drink plenty of water – 6-8 oz for every 15-20 minutes of activity. Pregnancy requires an additional 300 calories per day. A woman who exercises should add 150-250 more calories on top of that. However, the best way to gauge whether a pregnant woman is eating sufficient calories to ensure adequate weight gain. Pregnancy is not a time to diet or restrict calories!!! It is also not a time to binge and eat whatever you want!
Physical activity appears to benefit both mother and baby, and as long as pregnant women realize their restrictions, they may continue their exercise regimen without any negative consequences.