Trail Running During Pregnancy

Expecting with No Expectations- author: Devyn Thurber

After eight months of trying, my husband and I were overjoyed when we finally got a positive result on a
home pregnancy test. We are both in our mid-30’s and we knew we wanted kids (yes, plural) and we
were starting to feel the pressure of our biological clocks. When we made this decision, I was in the best
trail running shape of my life. No, I am not a professional runner and I do not depend on running as a
source of income for me and my family, but it has always held a very important place in my life. The
decision I faced is one shared by many female athletes (professional or not) – to put my fitness on hold
to start a family.

Determined to continue running, I started to peruse the internet for books and other resources to help guide my physical activity during pregnancy. As a medical professional, I was hoping to find some evidence-based literature about running while pregnant and was disappointed to discover that there is very little available on the topic. While I was confident that my uterus would not “fall out” as feared many years ago, I was pretty unsure about how best to mitigate other risks. Medical providers reassured me it was “safe,” but were unable to give me any specifics other than “stay hydrated,” “avoid temperature extremes,” and “stop if you have cramping/bleeding.” But I still had so many unanswered questions: Should I keep my heart rate low? Avoid trails to prevent falls? So, I turned to the stories of other female trail runners for guidance. The overarching message: listen to your body. So, this is what I did even though I didn’t always like what it had to say…

The First Trimester

During the first trimester, I mainly felt tired – really tired. This was actually the first tip off that I was pregnant. I was out running a usual route around town at a low effort, and my heart rate was through the roof. The first few months can be a frustrating time – your body is still in shape and you haven’t gained a lot of weight, but your energy is basically gone. For me, this was compounded by working 60 hours per week. I would routinely come home after a ten-hour day at the clinic and lie down on the bed fully clothed, only to wake the following morning to get ready for work again. My energy was best first thing in the morning, but this was also when my nausea was the worst. During this time, I made an arbitrary decision to aim for about 30 miles per week, which is about half of what I had been doing prior to pregnancy. For me, having a goal helped to motivate me during this tired phase. Having a running partner also helped. I felt lucky that my husband was willing to run with me most days, even if it meant he sometimes sacrificed his own training to do so. Though it was often difficult to get out the door, I always felt better (mentally and physically) after I ran and I tried to focus on this. I learned early on in pregnancy to monitor my perceived effort and to not compare my efforts to other people or my former self. This is easier said than done, especially with tracking software like Strava that shows you how your run that day compares to other “matched runs” you’ve done in the past and that notifies you when other runners have taken your fastest known times on certain routes. I know that, for this reason, other female runners have opted to take a break from these types of programs during pregnancy.

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The Second Trimester

As for many women, my energy returned and my nausea dissipated during the second trimester. This was really the golden time of running for me during my pregnancy. While I was slowly gaining weight and my belly was slowing growing in size, I was able to keep the rest of my body in shape for the most part with shorter runs and occasional lifting. I continued my goal of 30 miles per week at a low effort and aimed for one eight- to ten-mile “long run” at some point during the week. I was also able to get some time on trails in the mountains during these months, careful to avoid super technical terrain due to the shift in my center of gravity and fear of falling face first. Inevitably, my growing belly put increased pressure on my bladder, so I tried to stick to routes in which there were opportunities for multiple pee breaks (mainly in bushes on the side of the road or trail). No exaggeration, sometimes I needed to stop every mile on a run. Running with a support belt was a lifesaver from this point forward – it helped to cradle my expanding belly, taking pressure off my lower back and bladder. Buying larger sports bras was also helpful as I learned to run with large breasts for the first time in my life. During this time, my running clothes also stopped fitting – my shorts became uncomfortably tight around my hips and thighs and my tops turned into belly shirts. To my surprise, the market for pregnancy active wear is extremely limited. Instead, I bought running shorts one to two sizes bigger than my normal size and used cotton t-shirts from the pregnancy section at Target for running tops. 

While modifications to my wardrobe were helpful in accommodating my growing body, none of them were able to address the intermittent sacral pain that started for me during the second trimester. I learned that the pain is the result of softening pelvic ligaments that prepare the body for birth. For me, only running caused the pain and taking a break from running cured it temporarily. Thus began my renewed relationship with cross training. Towards the end of the second trimester, I began alternating running with using the elliptical every other day. For me, it was important for my mental well being to stay active every day – even if that meant that activity was not always running.

The Third Trimester

The third trimester is when I really felt the wheels come off during my pregnancy and I had to change my mental approach to being active. The size of my belly increased quickly (sometimes it felt like overnight!) and I started to gain weight more readily. For the first time in my life, I felt like an alien in my own body. As a competitive runner, I struggled with an eating disorder for most of my college years. The third trimester of my pregnancy was the first time since my recovery that my issues with body image truly resurfaced. I felt big and heavy, and while I knew there was a good reason for this, it was difficult for me to make that connection in my mind. To make matters worse, it became much more difficult for me to use physical activity as a way to mitigate these thoughts and this stress. The baby put increased pressure on my diaphragm and I felt short of breath more often than not. The fatigue from the first trimester returned (likely from hormones and poor sleep) and was coupled with painful swelling in my feet and lower legs. For all of these reasons, running became very uncomfortable, so I had to transition to lower impact activities for the remainder of pregnancy. I still tried to be active most days, but usually limited it to about 30 minutes per day on the elliptical or hiking on the treadmill. This also meant spending more time exercising inside, which likely did not help my mental health. If I had it to do over again, I would have opted for more time being active outside – even if this meant sacrificing the quality of the workout.

The Fourth Trimester

Throughout pregnancy, my husband and I had been hoping for a natural birth through a local birth center. However, some unexpected complications late in pregnancy led to a scheduled c-section. As I write this, I am recovering from surgery while adjusting to nursing and being a new Mom. I am patiently awaiting the day that I can return to running pain-free post-partum. In the meantime, I reflect back on the last nine months and agree with the advice given by other female runners about running during pregnancy – to listen to your body and to let that guide your effort level and training. There has to be a shift in mindset to focusing on being active for the sake of your physical and mental well being, not for performance. Any bigger goals outside of that may lead to disappointment and add unnecessarily to the other stress that already comes with being pregnant. For me, I found the most rewarding training plan while expecting was simply to have no expectations at all. 


Devyn Thurber, MSN, MPH, PNP-BC, is a competitive trail runner who lives in southern Arizona with her husband, Patrick, son, Arlo, and their two dogs, Cacho and Mani.

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