In decades past, pregnant women were encouraged to take it easy and rest up in preparation for labor and motherhood. However, contemporary research shows that being inactive during pregnancy does more harm than good—making labor more difficult and increasing your risk of postpartum complications like bladder leakage and hemorrhoids. As new information about pregnancy exercise circulates, you may be wondering how to work out safely without risking overheating or oxygen deficiency (hypoxia). Thankfully, there are plenty of pregnancy exercises that come highly recommended by professionals—and swimming tops the charts.
For Your Health
Though some women discontinue exercise as soon as they find out they're expecting, it's not the healthiest choice for you or your baby. The American Pregnancy Association and the National Health Service of the UK both recommend moderate exercise (about 150 minutes per week) all the way through your third trimester to allow for shortened labor, pain management during childbirth and decreased weight gain during pregnancy. You'll also reduce back pain, prevent constipation, and reduce your risk of gestational diabetes and cesarean section, according to the American College of Obstetricians and Gynecologists.
For Your Baby's Health
Research shows that babies born to mothers who exercised throughout their pregnancy are physically healthier and more developmentally advanced than babies born to mothers who were inactive during their pregnancy. In their book, "Exercising Through Your Pregnancy," James Clapp and Catherine Cramm point out that one-year-old babies of moms who maintained an exercise regimen performed better on the Bayley Scales of Infant Development test compared to the one year olds of moms who didn't work out. At five years old, children of exercising moms were in better physical health, weighing less than the five year olds whose mothers failed to exercise regularly.
Though any exercise you can muster is better than none at all, the American Pregnancy Association specifically recommends swimming as a safe pregnancy exercise for a number of reasons. Swimming is low-impact, relieving pressure on the joints and bones. Water-based exercise also reduces the risk of overheating and injury while providing a safe workout modality. While some intense land-based exercises can be harmful to an unborn child due to hypoxia (lack of oxygen) and heightened blood pressure, swimming keeps the heart rate low while still challenging the cardiovascular system, according to research published in the International Journal of Sports Medicine. And, thanks to water's hydrostatic pressure, swollen feet and ankles will subside, and blood flow will increase.
Is Pool Water Safe?
Although swimming itself is a perfectly suitable activity for nearly all pregnant women, finding a safe aquatic environment to swim in is paramount to your baby's health. Studies suggest that heavily-chlorinated public pools (like a YMCA or other community pools) might be hazardous to your baby's growth—possibly causing birth defects like low birth weight and neural tube defects. A 2002 study conducted by the Imperial College of Science, Technology, and Medicine in London found the presence of trihalomethanes (THMs) in pool water that was disinfected with chlorine. The study's author, Dr. Mark J. Nieuwenhuijsen explains that THMs occur when chlorine reacts with organic matter like skin cells, hair and soap residues, and making public pool environments more hazardous than home pools. Nieuwenhuijsen found higher levels of THMs in pools that were highly active and turbulent. But don't let that scare you off swimming. A 2002 scientific review in the journal "Epidemiology" examined the relationship between swimming in chlorinated water and birth weight. Researchers concluded that "[t]here appears to be no relation between the duration of swimming and birth weight."
Instead of swimming in a public facility, seek out a pool that utilizes a salt chlorination system which is much gentler on the human body and does not emit the odor or cause the irritating affects that traditional chlorine pools do. If you have the options, a saltwater pool, a home pool or the ocean are better choices than YMCA's and other public pool settings.
Of course, you should check with your doctor before starting a new exercise regimen, especially if your pregnancy is considered "high-risk" or you haven't worked out for a while. Once you get the go-ahead, seek a safe water environment like a backyard pool or a calm saltwater locale (like an inlet or tidal pond) and start reaping the many documented benefits of swimming during pregnancy.
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