In this special guest article by midwife and prenatal run coach Acadia Gantz, she guides us through everything related to running while pregnant – breaking it all down by the 3 trimesters.
We’re going to get into
In this article, we will break down the top three things to consider when running during each trimester of pregnancy.
We’ll also look at whether it’s safe to run while pregnant, and share plenty of handy tips for prenatal runners to maintain a healthy routine!
As with all exercise, it is important to discuss running in pregnancy with your healthcare provider to make sure it is safe for you and your baby.

Running During Pregnancy – Is It Safe?
Those two pink lines.
Whether planned for or a complete surprise, they come with a range of emotions, from excitement to anxiety and everything in between.
Regardless of the initial emotions, when a runner finds out they’re pregnant, one of the first thoughts is often “I hope I can continue running!”
Despite previously held beliefs about exercise in pregnancy, we now know that exercise, including running, is not only safe . . . but is in fact beneficial.
Exercise in pregnancy has numerous benefits for your developing baby including lowering your chance of preeclampsia, gestational diabetes, and preterm delivery.We also know that running makes us feel good! It reduces the risk of pregnancy-related anxiety, depression, and body image concerns.
The American College of Obstetricians and Gynecologists currently recommends that people with low-risk pregnancies should get 20-30 minutes of exercise on most or all days of the week.
Despite this being the current recommendation, you do not need to limit your exercise.
In general, you can expect to safely maintain the level of exercise you were doing prior to pregnancy, with appropriate guidance and a healthy respect for the boundaries your body has.
Pregnancy is unlike any other time of a person’s life.
Many changes are taking place, and not just physically.
There are mental, emotional, work, and relationship shifts happening as well, and all of these can affect not just your running goals, but also your daily running habits.
Related: 13 Tips To Balance Being a Runner and Having Kids

Running During The First Trimester
Here are the top 3 topics that come up when working with first trimester runners:
1. Will I get too hot for my baby?
You may hear concerns about an increased core body temperature causing neural tube defects in the baby.
This is particularly a concern in the first trimester, however, your core body temperature would need to exceed 102 degrees Fahrenheit for this to become a concern.
You are unlikely to reach this core body temperature simply from exercising.
However, it is smart to avoid running in the heat of the day, wear loose-fitting clothing, be sure to stay well hydrated, and stop or slow down if you begin feeling overheated, short of breath, or lightheaded.
Note: Using a sauna or a hot tub should absolutely be avoided during pregnancy.
2. Talking Morning (and beyond) Sickness
For many pregnant folks, the first trimester is a time of nausea, vomiting, and extreme fatigue.
While exercise can help with some of these symptoms, it is important to respect your body’s needs during this time.
Figure out what time of the day you feel best and plan your workouts for when you have the most energy and the least amount of nausea.
Be sure to eat a healthy, high protein snack first thing in the morning (having a high protein snack right before bed or in the middle of the night can also help with nausea!)

A handful of nuts, a cheese stick, low sugar protein bar or a piece of fruit with nut butter are all good morning snack options.
If possible, try to eat something before you even sit up in the morning.
Sometimes water can make you feel nauseous in the first trimester of pregnancy, but hydrating is always important, especially for runners!
Try making a simple lemonade by mixing a pinch of salt, and a splash of lemon juice and maple syrup into your water. Not only will this be easier to absorb by your body, but it also provides electrolytes.
Carry a small, easy-to-digest snack, and water, on all runs, and sneak a few ginger or peppermint candies into your pocket or sports bra incase nausea strikes on the run!
3. Fatigue
Do not feel guilty for choosing to nap instead of going for a run, your body is busy making a human and you need rest!
A good rule of thumb is to get out the door and commit to running or walking for 10 minutes.
If you still feel exhausted, go home and nap.
If you feel energized, then continue your run or walk.
Intervals are also a great choice for running while pregnant in the first trimester when your energy levels are much lower than normal.
Avoid caffeine or other stimulants, as they can affect the placental blood flow and potentially restrict your baby’s growth. (One small cup of coffee or tea a day is ok.)
The Second Trimester – 3 Things To Consider

1. Consider Your Nutritional Needs
As your baby grows, your nutrition needs grow with them.
Most pregnant folks need an additional 300 calories during the second and third trimesters.
However, this is not an excuse to pile on the ice cream!
Choosing healthy and nutritious foods is even more important in pregnancy.
Focus on a balance of protein, fresh fruits and vegetables and healthy fats.
(Of course, the occasional treat is important too but try to eat high sugar foods in the middle of the day, or before dinner, to keep your blood sugar stable overnight.)
2. Welcome To The Honeymoon Phase of Pregnancy
Many pregnant people refer to the second trimester as the “honeymoon phase” or as their favorite part of pregnancy.
For many people, nausea and vomiting have subsided and energy levels are much higher than in the first trimester.
And while your baby bump may be noticeable, it is not as big as it will be in the third trimester.
Take advantage of feeling good during this trimester.

If you want to participate in a race during pregnancy, now is a good time to find one, or simply enjoy the way it feels to run with your baby on board.
If you do plan on racing during pregnancy remember that even in a competitive setting it is important to respect your body and your baby and do not push past feeling good.
3. Meet The Relaxation Hormone
Relaxin, aptly named as it helps your joints and muscles “relax” in preparation for birth, will soon become apparent in your body.
You may notice that your joints feel loose or more unstable. It is important to pay attention to your posture and avoid overstretching your muscles and joints, particularly when doing activities such as strength training and yoga.
Relaxin is also responsible for GI distress that can appear in pregnancy such as constipation, diarrhea, and heartburn. Your midwife or doctor will have suggestions to help relieve some of these uncomfortable pregnancy side effects.
The Third Trimester – 3 Things To Consider

1. My Body Feels so Different!
The third trimester is when your belly has really “popped.” For some people, this is really fun and exciting and others can find it uncomfortable both mentally and physically.
It is important to acknowledge all your feelings about your changing body and know that they are all valid! As your uterus and growing baby are getting bigger, your blood volume is also expanding, and your breasts are changing in preparation for breastfeeding.
2. Why is running hard in the third trimester?
All of the changes your body is going through can lead to you feeling heavier, slower, and like running is just plain harder, and that is ok.
The third trimester is a great time to shift toward more walking or walk/run intervals.
Continuing to get outside and move your body, even if it is less than you were used to previously, has the same health benefits for you and your baby without the increased stress on your body.
Swimming, Tai Chi and prenatal yoga are also great options for third-trimester exercise.
3. Using running to prepare for birth
Have you ever heard of birth being compared to a marathon?
Well, there is a reason for that!
Giving birth takes mental and physical strength and resilience, and who would be better prepared for that than a runner!
Not only does running while pregnant give you the physical strength and stamina for giving birth, but it’s also a great time to practice positive self-talk, pick your favorite birth mantras, or meditate to your favorite playlist.
As a bonus, the snacks you use to fuel long runs are also the best type of snacks to have on hand for labor!

Running While Pregnant – More From Acadia:
Running during pregnancy is generally regarded as a safe activity for people with a low-risk pregnancy – however, it is not a time to push past your body’s early warning signals.
Take your pregnancy one day at a time and don’t get discouraged if there are days that you don’t feel like running, switch to a walk, or go home and nap and try again the next day.
Moving your body in any way that feels good has great benefits for you and your growing baby.
Acadia Gantz, midwife, is a running coach based out of Naples, Maine who works with many prenatal runners. Find her over at Canyon Wren Coaching.
