Exercise during pregnancy can be daunting but we spoke with three experts about how to make it safe and effective and what to expect from your body at every stage.
If you’re an expecting mother, pregnancy can make your body feel foreign even at the best of times. But, the good news is you can still make fitness a top priority. Exercise during pregnancy builds your muscles, provides more energy and keeps you healthy. It also helps you mentally and physically survive nine months of change and prepare for delivering a baby. Three experts describe what happens to your body every trimester of pregnancy, and how that may or may not impact your workouts.
The First Trimester: Embrace a Slow and Steady Approach to Fitness
“During the first trimester, exercise may not be a priority,” explains Sheryl A. Ross, M.D., “Dr. Sherry,” an award-winning OB/GYN, entrepreneur and women’s health expert. “You are feeling tired, nauseous, and experiencing breast tenderness during the first 13 weeks of pregnancy and you may not want to exercise.”
Your Body is Changing
Being exhausted is very normal, as most pregnant women have some degree of fatigue in the first trimester which can compromise their workouts, notes Mary Jane Minkin, M.D., Clinical Professor, Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine.
“In the first weeks of pregnancy, before you even know you are pregnant, hormonal changes occur,” shares Susan Hernandez, CNM, MSN, ARNP, UnityPoint Health. “These hormones help grow and support the pregnancy, while others work to stimulate milk production. While your first symptom is usually a missed period, these hormones will also contribute to sensitive or tender breasts. You may experience nausea with or without vomiting, fatigue, increased need to urinate and food aversions. Some women have heartburn and constipation. You will experience emotional changes and notice that your emotional needs are different.”
“The overriding change in women’s physiology is the increase in circulating fluid volume (i.e., the blood supply in the ‘tank’),” Dr. Minkin continues. “The fluid volume increased about 50% over the non-pregnant state; it doesn’t do too much changing in the first trimester, increases substantially till the end of the second trimester—and levels off there—and you lose the fluid at the time of the delivery or shortly thereafter. In other words, yes, you pee a lot, as us former pregnant moms know!”
Take It Slow
Walking at least 5-10 minutes a day plus Kegels to strengthen your pelvic floor muscles, is a great start to a healthy exercise routine, says Dr. Sherry. “Kegel exercises strengthen the pelvic floor muscles, which support the uterus, bladder, and bowel. There are many reasons why you can weaken your pelvic floor muscles, from pregnancy and childbirth to aging and being overweight. The effect of weakening the pelvic floor results in your pelvic organs dropping and creating a bulge into your vagina. When this occurs it is called pelvic organ prolapse. Symptoms from a prolapse range from an uncomfortable pelvic pressure to leakage of urine. Kegel exercises can help delay or even prevent pelvic organ prolapse and other related symptoms.”
Dr. Minkin encourages pregnant women to keep working out in the first trimester as long as they feel okay—with a couple caveats: “Even in the first trimester, when you aren’t that uncomfortable, don’t get your core temperature up too high. We do know that a core temperature of about 101 is not good for fetuses, so I discourage my runners from going more than 10 miles on a regular basis; and for folks who aren’t distance folks, to keep it to 5 miles. So lots of fluids, avoid high temps, and stop if you cramp—those are pretty straightforward.”
Hernandez advocates for walking, swimming, stationary cycling, or using the elliptical, as safe ways to exercise during pregnancy, in addition to yoga, pilates, water or low-impact aerobics. “If you feel really sore the next day you probably overdid things,” she offers as a gentle reminder. “You may need to take it a bit easier the next time you exercise.”
The Second Trimester: More Energy Leads to Huge Benefits While Working Out
Dr. Sherry says most women have more energy in the second trimester of pregnancy and will be more inclined to exercise more regularly. But because pregnancy affects joint stability, balance, coordination, and heart rate fluctuations, she urges women to talk to their doctor or healthcare provider to discuss any potential restrictions on activities chosen.
However, the second trimester is when working out can become a bit of a chore.
Everyone is Different
“In the second trimester, you are dealing with this increasing fluid volume and as the uterus increases in size, it mechanically starts pushing up the abdominal contents on the diaphragm, so you may feel like you are having more difficulty breathing—but you probably are breathing fine,” says Dr. Minkin. “Also, when you exercise you may start experiencing uterine contractions. I always laugh that I read an article by the great runner Mary Decker Slaney who stated that she started cramping at 20 weeks gestation, so she switched to fast walking. I personally didn’t start cramping with running until about 23 weeks, so I always told folks, see I must be a better runner than Mary Decker. Ha! But if you do start cramping with running, just switch to fast walking, and you’ll probably do better.”
And if running isn’t your mode of choice, know that most forms of exercise are safe during exercise. “Brisk walking, swimming, recumbent cycling, and strength training are excellent sources of exercises,” says Dr. Sherry. Dr. Minkins seconds swimming, adding, “Swimming is terrific for just about everybody—and by the third trimester, it may be the only time of the day you feel comfortable. I went for a 3 mile walk and a half mile swim the day before I delivered my first kid (I think I did it before my second kid, too, but I was too busy to remember!) and the swim was just fantastic.”
Unsurprisingly, expectant mothers should avoid certain high-impact or contact sports, such as soccer, basketball, snow skiing, and scuba diving—and per Dr. Sherry, you “should not start any new or rigorous exercises during pregnancy unless you speak to your doctor or healthcare provider.”
Don’t Overdo It
In terms of modifications or warning signs, Dr. Sherry says to completely avoid exercise on your back after hitting 20 weeks, since it can affect blood flow to the baby. She also doesn’t rely on heart rate monitoring as a key metric during prenatal exercise.
“Heart rate monitoring is an outdated and old recommendation for assessing how hard your body is working during your workout,” she explains. “If you exercised regularly before you got pregnant, you don’t have to worry about monitoring your heart rate during exercise. Exercise increases the flow of oxygen and blood to the muscles being worked and away from other parts of your body. If you are able to talk normally while exercising, your heart rate is an acceptable rate. Currently there is no specific recommendation for your heart rate during exercise for pregnant women. The main point is not to overdo it!”
Overall, exercise is great for those in their second trimester. “Exercise can reduce backache, constipation, help you sleep better, improve your energy levels, increase strength, and improve muscle tone,” says Hernandez. “It will help stabilize weight gain as well. I recommend 30 minutes a day of moderate exercise. You may do more or less depending on your fitness level.”
The Third Trimester: Regular Exercise Helps Prepare for Labor
According to Dr. Sherry, it is vital to stay active during the third trimester, even if you feel more tired. A regular exercise routine may not only help you feel less bloated or swollen, but “give you more energy as you head down the home stretch.”
There Are Major Benefits
“In the second and third trimester, the nausea and vomiting should taper off,” states Hernandez. “Your energy should increase and your center of gravity changes as the uterus get bigger. This pulls the spine forward so balance may be affected. Your joints will be more mobile due to hormones that promote joint relaxation. It is important to listen to your body, and to use good body mechanics. Also, there may some medical conditions or pregnancy that prevent you from exercise, such as preeclampsia, preterm labor, severe anemia.”
For the most part, these experts say exercising while pregnant can benefit your health in key ways:
- Helps reduce backaches, constipation, bloating, and swelling
- May help prevent or treat gestational diabetes
- Increases your energy
- Improves your mood
- Helps with concentration
- Improves your posture
- Promotes muscle tone, strength, and endurance
- Helps you sleep better
- Improves your ability to cope with the pain of labor
- May make it easier for you to get back in shape after the baby is born
But Always Listen to Your Body First
However, listen to your body and be mindful while exercising as an expecting mother, no matter what trimester you’re in. “If you start contracting, stop what you’re doing, and really hydrate,” emphasizes Dr. Minkin. “Drink a lot of water, and get off your feet.” Dr. Sherry says to stop exercising and call your doctor or healthcare provider if you experience any of these symptoms or warning signs:
- Vaginal bleeding
- Dizziness or feeling faint
- Increased shortness of breath
- Chest pain
- Muscle weakness
- Calf pain or swelling
- Uterine contractions
- Decreased fetal movement
- Fluid leaking from the vagina
As a whole, the benefits are vast for mothers looking to keep up an exercise regime and stay fit during pregnancy. “Exercise during pregnancy can help prepare you for labor and childbirth, and postpartum exercise can help you get back into shape,” says Dr. Sherry. “There is no question that the benefits of exercising during pregnancy outweigh the risks.”
“Exercise benefits pregnant women in many ways,” agrees Dr. Minkin. “It eats up calories, and most of us could afford to burn a few. More importantly, it gets us in training shape for labor and birth. How many runners would do a marathon without training? Labor and birth are the most aerobically challenging events that most women will experience. Why not train for them with exercise?