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Running While Pregnant: 5 Must-Know Modifications Per Trimester

I’ve been a casual runner since 2012 and the sport is part of my life now. It helps to relieve stress, re-focus and keep my weight under control. When I found out I was pregnant with my third baby, I knew that I wanted to maintain my running schedule as much as possible. I’m sharing my own pregnancy running lessons and tips for running while pregnant, broken into modifications per trimester. This is how you’ll keep logging some miles and feeling good about it.

How to run while pregnant and 5 modifications to make each trimester. #RunningWhilePregnant #FitPregnancy #HealthyPregnancy

First off, every woman needs their doctor’s approval to exercise while pregnant. Typically, the rule of thumb is not to start any new exercise regimen while you’re pregnant. If you were participating in the activity before becoming pregnant, you can keep doing it. 

Talk to your doctor at your first pre-natal visit about your planned exercise regimen. Don’t be afraid to ask questions and discuss a plan that’s appropriate for you. Even if you’ve been a runner for years, you should still seek your physician’s advice. 

Road Racing While Pregnant

Before we discuss normal running, let’s talk about the addictive feeling of running a race. I ran a Run Disney race, during my first trimester, while pregnant. I’ve seen many women on race courses who are pregnant. It CAN be done, but it isn’t advised for everyone. 

For my third baby, maintaining a consistent running schedule has been far more important to me than running a race. It depends what your goals are. I know many women sign up to run road races months in advance before finding out they are pregnant and want to complete their goals.

You really just have to change your mindset. Allow yourself to walk and focus on your body when you’re racing. Modify according to the weather. Do not rely on water stations. Instead, bring water and fuel sources that you can depend on.

Lastly, don’t forget to put your emergency contact on the back of your bib. That’s so easy to forget about. I also give someone my tracking information to track my bib during the race.

Road racing, Racing during your first trimester, Racing during your second trimester

Running While Pregnant: 5 Modifications Per Trimester

My biggest regret with my first pregnancy was not maintaining my running routine. By the time I gave birth, I felt like I was starting back at square one. With my second child, I maintained running for a bit – even raced in a half marathon – but then stopped cold turkey. Now that I’m pregnant with my third, I’ve maintained running and realize it is NOT all or nothing. The key is to listen to your body and modify as needed. 

Running While Pregnant: Your First Trimester

For many women, your first trimester is all about survival mode. Some go on to feel pretty normal, some ladies have extreme morning sickness and other women just have bouts of sickness. It’s hard to call until a few weeks after you take that positive pregnancy test. 

During my first trimester, my breasts hurt a lot. A great sports bra really helped to keep me running. Bouncing breasts only made things more tender. I had morning sickness, but was able to control it with natural morning sickness remedies

Running during your first trimester doesn’t have to change too much, but you should keep track of your caloric burn. Make sure you’re getting proper nutrition and not burning too many calories on top of feeling ill.  If you can’t keep any food or hydration down, then you don’t want to overdue the exercise. Dehydration is very dangerous while pregnant. 

This goes for many scenarios while pregnant, but contact your doctor if you have any bleeding or abnormal discomfort.

First Trimester Running Modifications:

  • Cut back on your caloric burn by running for less time
  • Keep your intensity level in-check by ensuring you can hold a conversation still
  • Modify your normal hydration to get more (switching from water to sports drink)
  • Invest in a nice fitting adjustable sports bra that can change as you grow – SheFit is my go to
  • If you’re in a hot summer climate, consider going indoors until the weather changes to help stay hydrated

First Trimester Running, First Trimester Exercise Tips

Running While Pregnant: Your Second Trimester

Once the woes of your first trimester clear up, you start re-gaining your energy and feeling much better for the second trimester. The second trimeter is the glory days of running while pregnant. You’ll be able to maintain your running without feeling too bad. 

My second trimester allowed me to run outside again. I modified several aspects, but felt really good overall. That’s also when I was starting to see that running was helping with my weight gain. Exercising really helps to not gain weight too quickly while pregnant. For the first time too, I felt good about my changing body. I attribute that to running.

The biggest struggle for a lot of second trimester women is the start of lightening crotch and round ligament pain. These can definitely be uncomfortable if you’ve never experienced it previously. If I feel those symptoms, I never “run through the pain.” Instead, I stop to rehydrate and rest. However, wearing supporting pregnancy pelvic belts can really help alleviate the symptom.

I also switched to running intervals while pregnant. I found that it helps to maintain my energy for a longer amount of time and I didn’t feel as bouncy. Eventually, if you want to run while pregnant, you’ll have to modify to keep it up. Walk breaks are an easy modification.

Second Trimester Running Modifications:

  • Switch to a run-walk-run as needed
  • Invest in a pregnancy support belt to prevent pressure on your crotch
  • Wear supportive leggings – I like Blanqi or Zella 
  • Keep your hydration efforts up and ensure that your caloric intake has increased
  • Pay attention to any feet issues – heel pain could be a sign of plantar fasciitis 

Second Trimester Running Tips, Running While Pregnant

Running While Pregnant: Your Third Trimester

Your third trimester goes back to being tricky again. I advise that you talk to your physician again to double check that you’re ok to keep running. This is especially true if you’re diagnosed with anything – like Gestational Diabetes. It’s always good to keep the discussion open with your physician. 

You’re kind of going back to survival mode again. Switch to running if you need to. Cut back to 1-2 running sessions per week. Make sure you’re getting the necessary calories in. If you feel Braxton Hicks contractions, and it makes you feel uncomfortable, then stop.

Many women have to modify by the third trimester. Don’t feel bad about it. Do what you can do on the days you feel better. It’s about staying healthy and not pushing yourself.

Third Trimester Running Modifications:

  • Use running intervals or just walk all together
  • Cut back on the amount of exercise time and mileage
  • Stop if you have any signs of labor or Braxton Hicks
  • Do not run too far away from your home and always have a phone nearby – Tell a friend or family member that you’re going to be running
  • Watch your balance while running. Your center of gravity will be off and you can’t look down to see your footing
  • Don’t try to induce labor via exercise, unless you have your doctor’s approval 

Third Trimester Running Tips, Walking In Your Third Trimester

Hopefully, with these tips, you can feel good about running while pregnant. If you can’t run anymore, look into low impact exercise, like swimming and pilates. It’s not all or nothing. It’s about trying to maintain your fitness. Even if you can’t run, you’ll be keeping your endurance up if you’re choosing not to sit on the couch.



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