This is a tricky question, given that most women will actually try to avoid exercise while pregnant (the back aches, the feet swell, and that bulging belly definitely discourages physical activity), but if you’re really jonesing for an endorphin high, or you just want to be more proactive with your health while pregnant, Slate informs us that there is a way to do it safely.
First of all, a more general Canadian study of the effects of exercise while pregnant turned around some expected results: It’s good for you. Exercise while pregnant is shown to improve or maintain the mother’s physical fitness, and there were no adverse conclusions on the mother’s body or health or the health of the unborn baby.
That said, another study out of Villejuif, France, and published in the Journal of Epidemiology & Community Health found that it’s probably best to exercise in short bursts — maybe try the recommended 30 minutes a day, three to five days a week. The study also found that pregnant women who stood more than six hours a day for their job were 1.25 times more likely to delivery prematurely than those who did not.
Lastly, if you’re going to exercise, don’t overdo it. According to a study out of Norway, blood flow may be blocked to the fetus during more strenuous exercises. Researchers studied Olympic athletes who were familiar with pushing themselves in training and found that when their heart rate was pushed to more than 90 percent of their max heart rate, the heart rate of their growing baby decreased. This would go back to normal once the mother stopped exercising, but regular bouts of intense exercise like this could have adverse effects on the fetus.
To be sure you’re not overworking yourself or your baby, calculate your numbers and keep track with the help of a heart rate monitor. Your max heart rate is normally 220 minus your age. So if you’re 30 years old, your max heart rate is around 190, so to be sure you’re not exceeding 90 percent, you should aim to keep your heart rate under 170 beats per minute.
There are plenty of exercises that can keep you fit while posing no threat to the baby, such as Lamaze, yoga, or swimming. These low-impact exercises are also easier on your joints and work more on muscle tone and strength than burning calories. There’s a reason behind your cravings, so why indulge just to run it all off later? You’re creating a human being, sister, so revel in the one time in your life when you can truly enjoy what you eat!