Training Through the First Trimester


One of the first things people tell you when you get pregnant is that “a baby changes everything.” If you’re an active, fit woman to start with, one of the first things it will change is your training.

First, the good news (to go with your great news): Women who are already in good shape and on a regular training program are encouraged to continue working out throughout their pregnancies, says Katharine Wenstrom, M.D., director of the Division of Maternal-Fetal Medicine at the Women & Infants Hospital of Rhode Island. “I have patients ask me all the time if vigorous exercise can cause a miscarriage, and I tell them if it did, there would be no unwanted pregnancies in the world,” she says. “We tell them not to start a vigorous training program, but if they’re already on one, it’s OK.”

Obviously, your body isn’t going to change from the sleek, athletic machine you’re used to into something large and unwieldy overnight; at three months, your fetus is only the size of a walnut. And if you’re following a clean diet with good portion control and the recommended additional caloric intake of just 300 calories a day, you’ve only gained 2 to 4 pounds total. But your body is already making massive adjustments in preparation for what is going to happen down the line, and that may mean scaling things back a bit.

“The first trimester is probably the hardest,” says Tatum Maguire, founder of Total Mommy Fitness, a 6-year-old gym in Austin, Texas, which caters to pregnant and new moms. “Though you don’t have the belly to navigate around, you can have extreme fatigue, nausea and dizziness. So don’t feel bad if instead of lifting for an hour, you lift for 15 minutes and then take a 45-minute nap. Listen to your body, not your internal voice saying, ‘I should be able to push harder.’”

Pregnant women have long been advised not to let their heart rates creep past 140 beats per minute. However, the American College of Obstetricians and Gynecologists says that number is no longer a benchmark to worry about. A better way to measure exertion, Maguire says, is the talk test. “If you can carry on a conversation, you’re good,” she says. “On a scale of one to 10, pregnant women should never go beyond an eight. If you’re an athlete and used to going real hardcore, eight is your new 10.”

The area where you may feel your pregnancy the most during this trimester is in your joints. Your body is now manufacturing relaxin, a hormone that will relax the pelvic joints enough to let the baby pass through the birth canal. But just as cardio melts fat all over your body (and not just where you’d like it to), relaxin will affect all your joints, not just those in your pelvis.

“Warming up and cooling down is really important in pregnancy,” Maguire points out. “And it’s important to keep the integrity of your joints secure. If, all of a sudden, you can put your ankle behind your head, that doesn’t mean you should.”

Should weight-bearing exercises start to bother your joints, Wenstrom suggests heading for the pool. “You can get your heart rate up pretty high by swimming,” she says.

Diet will be a key consideration, both to support a healthy pregnancy and to set you up to bounce back into shape more quickly after delivery. In addition to staying well-hydrated — at least eight to 10 cups of water a day — and avoiding alcohol and smoking, American Dietetic Association spokeswoman Ruth Frechman, MA, RD, says it’s important to be mindful of food safety.

“No raw sprouts, raw eggs, raw fish, soft cheeses, swordfish or shark — anything that would be higher in mercury,” Frechman says. “In the first three months, you may not think of that stuff. Soft cheeses aren’t pasteurized, so there may be an increased risk of bacteria there. You’re building a baby. You’re building a life. It’s important to take it seriously.”