2nd Trimester: What to Expect from Running When You’re Expecting

What to expect from running when you're expecting
Jeff Forman/JForman@News-Herald.com

As promised, your favorite pregnant runner is back with our second installment ofย What to Expect from Running when You’re Expecting. This time I’m here to tell you of all the wonderful, and perhaps not so wonderful, things you might experience while running during your second trimester.

While the first trimester was all about surviving fatigue, nausea, constipation and other fabulous hormonal effects, the second trimester is often a blissful three months of enjoying the attention that comes with being pregnant, while feeling pretty awesome. Enjoy it while you can, because then comes the third trimester. But I digress.

Weeks 14 – 17 (Feeling SO Much Better!)

17 weeks pregnant and running 45-50 miles per week.

This is when things get downright good! As a lean runner you might start showing already. This is nice when you’re passing people out on the trails. You’re almost cerrtainly slower than you were before you were pregnant, but you could definitely push the pace a bit now and then if you felt like it. Running is generally way more enjoyable now that the risk of miscarriage has plummeted and you’re likely feeling a whole heck of a lot better physically too.

What got in my way the most this month all three times was the beginning of my Braxton-Hicks contractions during about the middle of this month. During the 16th week of my first pregnancy I actually went in to see the midwives about them because they were freaking me out. The good news is that I seem to get them a bit stronger and earlier than most, so you might not even notice them until weeks or months later than me.

This pregnancy the BH contractions started about 15-16 weeks and were particularly bad on some of my runs in hotter weather. I had one run, that I particularly remember, at 17 weeks. It was an evening run and it was really hot. I got a contraction as I started out, which wasn’t unusual, but it would not let up! I ran a mile before resorting to walking. I was really worried about it. But I drank my handheld full of gatorade and within a few minutes I was fine. I just kept drinking and refilling my bottle. From then on, if it was over 70 I brought my handheld and drank throughout my runs. I realized I not only had to drink on runs during which I would never have thought to stop when not pregnant, but I had to drink A LOT! If I didn’t, I’d become very crampy even long after the run was over.

So, even if you are not noticing contractions, I would recommend drinking a lot more than you normally would when running, particularly in the heat. The pregnant body abhors dehydration and is also more heat sensitive. The other thing you will need to remember, even during the relative awesomeness of the second trimester, is that you will have an increased need for sleep that you’ll take with you throughout your pregnancy. This might cut into the time available for running.

It is worth mentioning that a lot of women have a hard time ramping the miles back up after having to cutback so much during the first trimester. Don’t beat yourself up about running way fewer miles per week than you had hoped you would before you got pregnant. Remember, it’s temporary! You’ll get the fire back again when you have your body back to yourself!

Week 14

Week 15

Week 16

Week 17

Weeks 18 – 22 (Halfway There!)

20.5 weeks pregnant and winning my age group in a local and competitive 5 miler for the 5th time! (Last year I ran more than 5:00 faster, but who cares?!)

Now you’re probably really looking pregnant AND feeling great. These are the best weeks of pregnancy! If you’re finding out the gender, you’ll found out during this time which just adds to the awesomeness of this month. Plus, you’re halfway there!

I talked about the beginning of Braxton-Hicks above. Another issue with hydration is headaches. My second trimester fell squarely in the summer the first time and this third time and besides being hot it was often very sunny. Between the heat and the bright lights, I suffered from some severe headaches if I wasn’t careful. But once I started drinking much more heavily during my runs (water, silly!) and remembering my shades, I nipped this issue in the bud.

As for actual running, I made it 6 weeks or so running 45-50+ miles per week and felt pretty darn good! I capped off this period running my favorite race. It’s a local and competitive 5-miler put on by our area newspaper. Every year I’ve run it, my photo appeared in the paper the next day, 4 times as an age-group winner and, when I was pregnant the first time, a photo of me running in the middle of the pack. I thought for sure this would be the year I didn’t make the paper. I was wrong! Somehow, I ran a 36:21 and won my age group! Sure it wasn’t the most competitive year for 35 – 39 year olds, but heck, I’ll take it!

But like me, you might find you can still bust out some decent performances. I pushed myself in that race, but wasn’t close to redlining, and still far exceeded my expectations for myself. I will say, that I took it very easy for the few days after the race. I noticed that I needed a little extra time to recover from harder efforts while pregnant. The relaxin that allows your joints, etc. to stretch to make room for baby can do weird things to your hips, lower back and other joints, so it’s important to rest and recover as needed. This is NOT the time to get injured!

Week 18

Week 19

Week 20

Week 21

Week 22


23 weeks and appearing on the FRONT PAGE! of my local paper to discuss running during pregnancy. Image via Jeff Forman/JForman@News-Herald.com (Click on the photo to read the story!)

Weeks 22 – 26 (Mostly Feeling Good, but Very Pregnant!)

As you enter the last month of the second trimester you will likely still feel good most of the time. You might even have lofty ambitions to keep the miles up and maybe jump in a race or throw down a speedy mile here or there. But despite your best intentions, and sometimes much to your surprise, you’ll find you just can’t do what you want to do. I went to a family reunion during this month of my pregnancy. I had babysitters aplenty and a beautiful new place to explore, but with all the other activities of the week I was way too pooped to run anywhere close to the miles I had hoped. I also realized around this time that I could no longer do things like work at ourย farmers market stand for 3-4 hours shilling veggies on my feet and also run in the same day. If I overdid it one day, I’d pay the next day. I’d feel heavy and exhausted and sluggy.

That being said, when I did have the energy and the time, I was able to get in some good milage and some good runs. I ran my longest training run of this pregnancy at 25.5 weeks: 13.58 miles in about 2 hours and felt really good. During the last week of the second trimester, I had an opportunity to hit up the track with my teammates and I took it! It was mile time trial week so I thought it might be fun to see what I can do. Much to my surprise I ran a 6:32 and was even able to do the rest of the workout with the group!

I’d sum up my discussion of the second trimester with the advice to not fear a little ambition as far as running goes, but also to expect the need for extra recovery time. Also, know that when you’re non-running life demands more out of you than normal, you might have to shelf the plans to run. And as always, listen to your body!

Week 23

Weeks 24 & 25

Week 26

What was your experience running through the second trimester? Were you able to do as much as you wanted to? Do you have any questions or concerns about running during the second trimester?

For more in our What to Expect Series, go here for the first trimester and here for the third.

Salty Running boss and mother of 3 little ones with PRs of 3:10:15 (26.2), 1:25:59 (13.1) and 18:15 (5k). I love to write about running culture, mental training, and fitting in a serious running habit with the rest of a busy life.

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  1. I really enjoyed your post on running during your 2nd trimester. I am 16 weeks pregnant and I’m finding it more challenging to run due to the feeling of “having to pee” while running. Even if my bladder is not overly full, I find that at this stage of pregnancy the baby puts so much pressure on my bladder it can be very uncomfortable. Did you have this issue during your pregnancy? Any advice?

    1. Hi Rosanna –
      I am 25 weeks pregnant and down to running about 30 mpw these days. Like you, I’ve found the biggest challenge with running for two to be the tremendous pressure on my bladder, which started at only about 12 weeks. I am carrying this little guy so low! For a while, I found myself having to stop get some relief every 10 minutes or so, even though there was almost nothing in there!
      Some things that I have found helpful have been either refraining from drinking anything in the 45 minutes before I go run (although you should drink extra the rest of the day to avoid dehydration) or running first thing (after a trip to the bathroom and a little snack) in the mornings, when gravity hasn’t yet taken its toll on my belly. I’ve also started planning my routes to circle around park bathrooms and even back towards my house in case I have to make an emergency stop or three. On a final note, I head to the bathroom right before I leave, whether I feel like I need to go or not! It’s ridiculous.
      In the past month, I have started aqua-jogging once or twice a week, and the weightlessness is an amazing feeling at this point. Hope you get some relief soon!

  2. Currently I am 24wks with my 3rd and running 30-40mpw..lately my legs are locking up after about 1.5-2mi, it’s unbearable and I have to stop & walk. Did anything like this happen to you? I vaguely remember this happening during my 2nd pregnancy, but not with my first…

  3. Thank you…I wasn’t quite the runner you were..I was averaging 3-4 miles 3-4x per week and at 18 weeks I am struggled. I feel pretty intense inner thigh/hip/groin pain that has me switched to intervals. I am totally slow but trying to keep going. Thanks for sharing your experience!

  4. What a fantastic log of running experience during pregnancy! SO helpful since it’s extremly difficult to find good information.
    I ran through my pregnancies up until 6-7months when the Braxton Hicks contractions started as I found them so frustrating. I never tried tackling them by drinking a lot, it just didn’t cross my mind! I have stopped again now at 6 months(third pregnancy) due to the same issue, but might try at the weekend.
    Just to agree with other posts speed has gone down dramatically, but it isn’t about pace; it’s just so good to keeping it going as much as possible.

  5. Hi, I’m 16 weeks and 2 days. I had to give up exercise as advised by my midwife as I was spotting in the first trimester. We’ve now had our 12 week scan and have our 16week midwife appointment this week.
    I’m dying to get back into doing some proper exercise where I feel I’m actually working out. I wasn’t a big runner before but really enjoyed it. Would you advise that I start running again now as I haven’t done anything for the past 16 weeks?


    1. I spotted a bit around 6 weeks with my first and took about a week and a half off of running before resuming. I’d talk to your midwife about it, but if you’re cleared to exercise than running should be fine, but you’ll want to ease back into it since you took a break from it for a few weeks. Keep us updated on how things go!

  6. I love this series! I’m currently 23 weeks with my first–I had to take off running my first trimester due to exhaustion, but worked up and ran a 10k in a respectable time at 20 weeks. The problem is that I took a week off immediately following the race, and since then have had a terrible time working back up even to to 3 or 4 miles. I do my usual safe but intense stretching before I run, and then after about a half mile my calves start to cramp and tire enough that I have to stop and stretch by 1 sad, slow mile. I though that relaxin was supposed to make us all loose! Any thoughts/suggestions/ideas what the heck is going on?? (Note: I’ve been running for years, and even ran a marathon a few years ago, though I had more recently been doing about six miles at a time before getting all knocked up ๐Ÿ™‚

  7. I’m currently 18 weeks pregnant with my second and have been forced to run primarily on a treadmill because of incontinence. ๐Ÿ™ Still happy to keep my miles up, but just wondering if there is anything I can do and if anyone else experienced this? No matter how often I stop to go, the urge persists!!

    1. Hi Danielle! I found taking walk breaks helped on those runs when I felt bladder pressure. I don’t know why, but taking regular breaks from running helped. I also ran at the park a lot so there were bathrooms and learned a trick to pull the crotch of my shorts over so I could pee discreetly and just look like I was tying my shoes. Necessity: the mother of invention! Ha! Lastly, you might just give in and let yourself leak. Lube up, wear black or patterned spandex, possible a pad if that makes you feel better and go with it. Oh and bring a change of shorts ๐Ÿ™‚ You’re so not alone in this!

  8. First of all – I love this blog and knowing “what to expect”. I am currently 17 weeks pregnant with my 2nd child. Up until about 10 weeks I was keeping up with my 3-4 miles a few days a week schedule. At about 10 weeks the sickness became so bad that running was absolutely out of the question. I am now feeling great again and ready to hit the pavement. From your experience, is it safe for me to start again? And if so, any suggestions?

    1. First, you should discuss this at your next prenatal visit. But in general, it’s ok to ease back in after a lay-off during pregnancy. Just do what feels good. If running fatigues you, then maybe back off a little. Err on the side of slowly easing back into running … plan to mix in walk breaks and keeping your runs on the short end of your range and the slow end of your pace. And then go from there. Keep us posted!

  9. I love this blog! I’m a runner and mom of 2 expecting my 3rd at 23 weeks:) I have been told by the doctor on 2 occasions to “watch my weight gain”, which leaves me feeling really guilty and bad about myself. But after reading this it totally makes sense. My mileage has definitely decreased and my pace as well. But I’m happy to be running still, eating well and overall I do feel great. I just did a half marathon on Halloween and finished in 1:49, which I was very happy with at 22 weeks pregnant. Thanks for the reminders and confidence to keep it up!

  10. Hello, thank you for having written this blog, you have put me at ease. I found out that I am 6 weeks along earlier this week, which explained much about the fatigue I have been experiencing for a few weeks now. Anyway, with the fatigue riddle figured out, I got myself out of bed this morning and went for a 5 km run. I was pleasantly surprised at how good it felt. I was definitely slower, but I loved every step I took and how natural it felt to be out there. Furthermore, it seems my energy levels are still up and I could hardly take an afternoon nap, as I have been everyday for the past few weeks. I am due for a half marathon in March, when I will be around 20 weeks. I am feeling hopeful after today’s run- of course with (a lot of luck:)), care and thought into it- that I can still take part in the half marathon.

  11. I am currently 21 weeks pregnant and I can usually run anywhere from 4-6 miles a day/6 days a week. (Had 5 knee surgeries last year that prevent me from running longer.) Recently, in the past week or so, I feel like my belly tightens up making it difficult for me to run and breathe. Is this common? Is there something I can do to remedy this? I still want to run everyday bur some days I can’t because of this feeling.

    1. Definitely talk to your ob/midwife about it, but I would get Braxton hicks when running a lot and drinking water during the runs, which I don’t normally do, helped.

  12. This is my fifth pregnancy and my second running through it. My question is, do you believe you can continue to train for pace despite the slowing down factor. I’m frustrated because I don’t want to loose what I worked so hard for, ya know? Thanks for your positive thoughts and solid advice. It’s very helpful.