Is Strength Training Safe During Pregnancy?

Strength Training During Pregnancy

Have you just found out you are pregnant and wondering if working out is a good idea during these next 9 months? With my first pregnancy that was one of my biggest questions, so I searched high and low to find out what is the best thing to do for myself and my future baby. I found overwhelming evidence that exercise is good for pregnancy which I explain below as well as answer some commonly asked questions.

Prior to getting pregnant, I was hitting the gym 4 days a week and training for a powerlifting meet. So when I found out I was pregnant one of the first questions I had was if I could still work out. After consulting my OB/GYN and doing some research I was assured that it is completely acceptable to continue the type of training I was doing pre-pregnancy.

Keep in mind, I am giving information for low-risk pregnancies such as my own, if your pregnancy is high risk some of this may not apply to you. Please consult with your OB/GYN to make sure your workout plan will work for you.

What Are the Benefits of Prenatal Strength Exercise?

pregnant woman strength training

Some benefits to working out during pregnancy are:

  • less back pain
  • decreased chance of a C-section
  • avoiding excessive weight gain
  • easier/shorter labor and delivery
  • increased heart health
  • Excessive gestational weight gain
  • Gestational diabetes mellitus
  • Gestational hypertensive disorders*
  • Preterm birth
  • Lower birth weight

We have all been told that having a healthy diet and regularly exercising is good for the body, right? It’s no different during pregnancy. The American College of Obstetrics and Gynecology (ACOG) recommends women continue the level of exercise they have been maintaining or begin an exercise routine while pregnant.

I don’t know about you, but all of those sound like a great reason to get my fitness on throughout my pregnancy!

ACOG’s recommendations for pregnant women are 150 minutes per week of moderate-intensity aerobic activity. Now, I am partly biased in this but I personally think you should be doing some weight training as well. During pregnancy, we tend to lose muscle mass due to the hormones released so training our muscles to prevent loss will be very beneficial pre and postnatal. Thankfully, ACOG also states that resistance exercises including weights and resistance bands are safe and beneficial as well.

Pregnancy Body Changes That Affect Workouts

The body goes through a ton of changes during pregnancy which can make working out a different experience than prior to pregnancy. Things that can affect your workouts include:

  • increased blood volume
  • hip width
  • weight gain
pregnant woman powerlifting

Increased Blood Volume

When pregnant, women start producing double the amount of blood volume to circulate enough for the baby and mom. Once that started happening, I could tell my workouts were definitely harder. I would start my second exercise and be tired already. Since there is double the amount of blood, your heart has to accommodate the excess work. Not only that, you need to have more oxygen circulating through your body for you and your little one.

That’s why training your body to be able to adapt to those changes can help you greatly by the time you are going to give birth. A study was done and determined that women who had higher cardiorespiratory fitness had higher oxygen transfer capacity during the third trimester.

Hip Width

Another change I found was my hips widening. Your body will change to adapt and make it more optimal for giving birth. This can cause you to feel less balanced and have achy muscles. I needed to completely change the way I squatted 8 weeks into my pregnancy because of how my hips were feeling. So be prepared for some modifications to workouts and don’t compare pre-pregnancy to post-pregnancy workouts, it will leave you feeling disappointed.

Weight Gain

And the most obvious change- that big ole belly growing. It will get more difficult to hold weights in front of you when you already have a 10 lb. weight sticking out of you wasn’t there before.

What is a Dangerous Heart Rate While Working Out Pregnant?

There is no set number that is a dangerous heart rate during prenatal exercise. Since every woman has different exercise levels, it might be normal for one woman’s heart rate to reach 180 bpm and it can be dangerous for another. There is more evidence supporting the benefits of high-intensity workouts (which cause a higher heart rate) than there are warnings for it. If you have been doing HIIT workouts prior to pregnancy and you love them, keep doing it!

If you are just starting out and are worried about getting your heart rate too high, look for symptoms of overexertion. If you start to feel dizzy, feel like your heart is beating out of your chest, are so hot but not sweating— these are signs of overheating which are dangerous. You want to avoid any of those symptoms and work to lower your heart rate. Listen to your body— if it doesn’t feel right, don’t do it!

Also, if you are just starting a workout routine, don’t try to go from no exercise to pushing your body to its limits during this time. Any kind of movement that is more than what you’ve been accustomed to will help your physical fitness.

I want to stress the word movement: meaning if you come home from work and usually sit on the couch for the rest of the night, start taking a 20-minute walk around the neighborhood. There is no need to go from zero exercise to a 2-hour strength workout in the gym unless of course that’s what you want and your body can handle it. Basically, any type of movement is exercise that will increase your stamina and help build you up to more intense workouts.

Can I Tear My Placenta From Vigorous Exercise?

It is extremely unlikely to tear your placenta from intense exercise. Placental abruptions are a rare occurrence therefore, there is not a ton of research on them occurring specifically through exercise. There are a few studies done on women who perform intense training during pregnancy. A study was done on non-exercisers, regularly active, and highly active women and found that 30 minutes of moderate and vigorous exercise posed no deficit in oxygen to babies.

There are significant findings that women can continue exercise routines they had prior to pregnancy unless it involves physical trauma to the abdomen or unless the pregnancy is high risk. So if you have been doing strongman, powerlifting, CrossFit, HIIT training, Zumba, etc. I say go for it! For me, I just lowered my lifting sessions to 30 minutes and then did some stretching. 

This was a big concern for me personally since I train to lift maximum amounts of weight. Before I got pregnant, I was a powerlifter training for a competition. I wanted to continue to lift heavier weights but not endanger my baby. Of all the research, I cannot find anything to say that high-intensity exercise has led to placental abruptions.

What Are Signs I Should Stop My Prenatal Strength Workouts?

There are a few reasons why you should discontinue regular exercise and it’s important to be aware of what those are. No matter your fitness level if you experience any of these symptoms, stop and reach out to your OB/GYN:

  • Chest pain
  • Regular, painful contractions
  • Muscle weakness
  • Vaginal bleeding
  • Headache
  • Difficulty breathing before exercise
  • Calf pain or swelling
  • Feeling dizzy or faint
  • Fluid gushing or leaking from the vagina

Will You Choose to Strength Train During Pregnancy?

If you are looking to continue your fitness routine while pregnant I highly recommend it. Not only will it be beneficial to you and your baby, but it can also be comforting to keep a little piece of normalcy during this time of change if you are used to an exercise routine.

If you are just starting out, start small and slowly build up your exercise routine. Exercise does not need to be P90x or powerlifting— exercise can be a 10-minute walk each day that progresses to 30 minutes and maybe even an hour. It could be yoga, dancing, 50 squats, walking up your stairs 5 times a day—it can be whatever you need to get your body moving! Any type of movement is good for you and your baby during this time.

Do you plan to exercise during your pregnancy? If so, what’s your go-to workout? Let me know in the comments, I love hearing your experience!