Trail Running While Pregnant-Month by Month Breakdown

I love trail running! Being outside in the mountains hiking and running is my passion. When I got pregnant I knew that I still wanted to get out and do what I loved but everyone told me that I would not be able to. I couldn’t find hardly any information on trail running while pregnant so through a lot of trial and error I had to figure it out on my own. This was my experience.

Month 1-2

So typically you do not find out that you are pregnant until 3 or more weeks after conception and for many people they don’t even know for the first month or more. I have always struggled with irregular periods so although my husband and I were trying to get pregnant, the timing was very unpredictable.

I was signed up for a backyard ultra trail race in April of 2024. I ran it and ended up going 40 miles eating a big plate of sushi and then going to bed. The next morning I took a positive pregnancy test, I was so excited but wondered what this would mean for my passion of trail running.

Throughout the first and second month I reduced my running slightly partly due to pregnancy and partly due to runner’s knee. I used that time to do some climbing, and hiking and research on what it looks like to run while pregnant and learn how my body would adjust to this big change. I went from running 20-30 miles per week to 10-20.

10-20 miles/week– running and hiking (pre-pregnancy was on average 20-30 miles running per week)
Figure out your symptoms– Pregnancy effects every woman differently, find out how your body is adjusting.
Adjust your fueling and drinking– You will likely feel differently while running pregnant. This doesn’t always mean you need to stop sometimes you just need to adjust.
Make necessary adjustments to mileage and pace– you may not need to adjust right away but just like with fueling you have to re-learn what your body needs in this new condition.
Know the power of nutrition– Eating healthy in the first trimester played a significant role in my ability to stay active.
Make sure you are eating enough throughout the day– I had a significant appetite decrease at the beginning of pregnancy as well as a lot of different food aversions.

Month 3-4

By month 3 I had pretty much figured out my symptoms and learned how to control nausea and I was getting into quite the groove with my exercise. However, it was also starting to get hot out so I began to do a lot more hiking and focus on vertical gain. What worked for me in that time was to transfer my focus from milage to vertical gain and elevation training.

During this time I got the opportunity to go to Yosemite and hike half dome with my family which is a 16 mile hike with an elevation gain of 5,000 feet. My family was so worried about me doing the hike but I ended up having to stop and wait for them to catch up a lot of the time. I also had the opportunity to travel around Colorado and do a lot of cool hikes there.

At this point I was still able to run downhills and flats, and I was still able to do long days and feel pretty normal besides needing to fuel more and bring more water, but everyone is different. Listen to your body and the rate that your pregnancy and symptoms are progressing.

10-20 miles/week and 4,000-8,000 feet of elevation gain– This is an estimate, there is no need to be strict and to make sure that you are hitting these numbers. There is no need to do it if you are not enjoying it. If you are not enjoying it then find another way to be active that will make you happy.
Do not neglect hydration!– It can be a difficult switch but it is so important to make sure you always have enough water on the trail while pregnant. Experiment with what amount is right for you and pay attention to how you feel.
Fueling– You will get hungry more frequently throughout your runs. I went from eating every 45min-1hr to every 20-30 minuets.
LISTEN TO YOUR BODY– The most important thing is to listen to you body. Make the necessary adjustments. Make staying active your priority and do things that you love.
Keep yourself acclimated to high elevations– It is completely safe to keep going up to high elevations if that is what you are used to and acclimated to. You can even spend a few nights sleeping up in the mountains to help you.
Make sure to have good running form– don’t neglect your form. It is especially important as the bump gets bigger.

Month 5-6

At this point I was still focusing on vertical gain with some downhill running mainly due to the summer heat. I started doing less climbing (I did not do any lead climbing while pregnant, only top rope).

The biggest change that I saw at this time was an increase in my need to pee while running. I started needing to go every so often on big days and at least once on smaller runs.

At this point my long days became long hikes rather than long runs and I could run on the shorter days. By the end of month 6 I had reduced my runs to 5 miles or less.

10-15 miles/week– running and hiking
Keep fueling and hydrating– you are going to have to go to pee on the trail more often, especially on long days. Though it can be inconvenient, do not let it discourage you from drinking enough water.
Pay attention to your heart rate– This is good to do throughout all of pregnancy but especially at this point when the baby is having so much brain development. The rate will vary for everyone but it is generally best to stay in a zone 2 HR for most of your activity.
Do not look at your pace– Okay you don’t literally have to stop looking at your pace but right now that is not the important thing. You will likely be going significantly slower than you were before but pace is not the concern right now.
Dial back any scrambling– at this point you might experience a little bit of clumsiness and feel thrown off your center of gravity. So it is best to avoid anything where you could take a big fall.
Focus on your form!– this will help recovery after runs and help prevent pain and strengthen your body for birth.

Month 7-8

Months 7 and 8 is when the baby really starts to rapidly gain weight so you might be feeling a lot more tired. I had a lot of days when I was planning on doing something bigger and ended up needing to take that time to nap instead.

By the end of moth 8 I had to significantly reduce my milage due to pelvic pressure leading to pain. Most of my pain was pelvic girdle pain (PGP) I didn’t want to let this effect or lengthen my post partum recovery so I decided it was time to dial it back. My long days turned into 9 mile hikes then 5-6 mile hikes with my short days being 2-3 mile runs in month 7 and 2-3 mile hikes in month 8.

By month 8 I had to stop doing long days and focus on just consistently doing 2-3 miles everyday. This was hard at first and if I was itching to get out on a longer day I would just do 2 a days and do something in the morning and something at night.

5-15 miles/week– mostly hiking
Use your morning strength– your muscles and tendons will be a lot stronger in the morning. It is best to do your more strenuous exercise (like uphill hiking or treadmill incline walking or weightlifting) in the morning rather than in the evening when your body is tired. This will help prevent injury and overuse.
2-a-days– a lot of the time it can be hard to do the amount of exercise that you want to in the 3rd trimester. If you really want an long day try going on a hike in the morning and then walking another mile or two at night. It will help you get that exercise in without putting too much strain on your pelvic floor at once.
Pay attention to how your body feels (especially pain)– make sure to not hurt yourself or do anything that will just make your after birth recovery longer.
Take time to stretch– stretching can be so vitally important, especially at the end of pregnancy.
Keep up your good nutrition– with a decrease in activity sometimes it is easy to let our nutrition slip. Remember it is so good to help prepare for labor!
SLEEP!– for me months 7 and 8 was really when I felt super restless and had a hard time sleeping. What helped me was to get as much as I could during the night and then try to get a nap and some exercise in during the day. (This is not always realistic with work or school or other kids but it’s good to get it where you can.)

Month 9+

What an exciting time! Take this time to really listen to your body and what it needs. This doesn’t mean you can’t get out and move but make sure you are not overworking yourself and you wont be too exhausted to give birth. During month 9 I walked, hiked, climbed (with a pregnancy harness) and also had a lot of restful recovery days.

Take it easy– think of giving birth as a big race day. This is what you’ve been training for at these 9 months! Make sure you taper off your activity right before just like you would for a big race.
Prioritize what you enjoy– your mental health does not have to suffer just because you’re dialing back your mileage. Keep finding ways to get outside and do things that you love.
Keep walking– even if it is short, find time to get out and go for a small walk and get the blood flowing.
Don’t stop stretching!- Just because you’re no longer having those long days doesn’t mean that stretching isn’t essential. Remember, you’re prepping for your big race day.
Prepare yourself for post-partum recovery– be kind to yourself and don’t have too high of expectations for recovery. Remember, everyone is different and have unique experiences with labor and recovery.
GET EXCITED!– the big day is almost here! All of your training is about to pay off. Don’t be scared, tackle that big race day with excitement and determination. You can do this!

I hope that this was helpful for you to see that it is possible to keep adventuring and keep doing what you love during pregnancy. I am such a believer in prioritizing doing what you love and what keeps you excited no matter what stage of life you are in. A lot of people told me it was too hard to stay active during pregnancy but I know that I was truly nourished by motion throughout every month of my pregnancy adventure. Good luck mamas, and happy trails!

Nourished by Motion