Sunday, June 6, 2010

Angry and Frustrated - Pregnancy Running Heart Rate Test 1!

First, a special thanks to Matthew for letting me borrow his heart rate monitor GPS for the next few days.  Second, this 140 beats per minute limit when running heart rate rule for pregnant women is bunk! You can tell I'm still in the denial phase (although it is a completely arbitrary number).

I went out this morning about 9:20 am for my first heart rate test.  Resting heart beat was about 70 with about 80-90 as I moved around the house.  It's important to note how warm it felt out today - my route had no shade, it was full sun, 81 degrees, and humidity a little over 80% (whew!).  Noticed on initial warm up heart rate was 110.  I warmed up by walking and jogging for a few minutes and just getting used to the display's on this particular GPS.

Then, I performed a series of "tests".  3 minutes at different paces, each test followed by walk breaks of 1-3 minutes.  Thought process in italics.

Let's start with a pace that feels easy and natural.
3 minutes @ 11:29 pace: max heart rate was 164
1 minute walk break: heart rate back down below 140 in 46 seconds. 132 at end of one minute.

Okay, that was "allegedly" too fast, let's slow it down.
3 minutes @ 12:03 pace: max heart rate was 160
1 minute walk break: heart rate back down below 140 in 45 seconds. 132 at end of one minute.
Another 1 minute walk break: heart rate was 123 at end of one minute.

Fine, slow it down again.
3 minutes @ 12:29 pace: max heart rate was 164
1 minute walk break: heart rate back down below 140 in 55 seconds.  138 at end of one minute.
Another 1 minute walk break: heart rate was 124 at end of one minute.

Slow it down more? Shoot for 13:00, wow, that's too hard for me to slow down to that.
3 minutes @ 12:40 pace: max heart rate was 156
1 minute walk break: heart rate back down below 140 in 38 seconds.  132 at end of one minute.

Fine, heart! Let's see what you think of 5K PR pace:
3 minutes @ 10:30 pace: max heart rate was 174
2 minute walk break: heart rate back down below 140 in 1 min., 21 seconds.  130 at end of 2 minutes.

So basically, I can't run and keep my heart rate under 140?!? Try "purposeful" walk (not my fastest walk)
3 minutes @ 15:17 pace: max heart rate was 143.

WHAT? Now I'm frustrated and in tears.
Final 1 min, 34 sec of slow walking.
Heart rate 129 at the end.

Summary: All paces from 10:30 to 12:40 were "too much".  Although after 3 minutes, with most of those paces, I could recover within 45 seconds, which feels pretty good to me.  The purposeful walk was done after all the other tests but was still just a little over 140.  So I shouldn't be running at all?

I walked in the door and cried for a while - hubby patted my super sweaty shoulder, don't blame him for not hugging me. :-)  So right now, I'm angry and frustrated.  Based on 140 rule, I basically can't run and even a purposeful walk is kinda pushing it?!? And at only 13 weeks pregnant? And after running 30 miles per week earlier in the year!

I'm feeling like my doctor screwed me over.  She knew I was a runner and that I wanted to run through this pregnancy before I conceived.  Maybe we should have done more cardio tests to know what my aerobic and anaerobic personal thresholds were before pregnancy.  And I'm supposed to be testing my heart rate but we set up nothing more than my next check-up 4 weeks from now to complete that feedback loop.  Looks like I'll collect more data and call the doctor Monday to schedule something in a week to review all the data and decide what's best FOR ME and the baby - not just some generic rule.  I'm not ready to give up yet!

And what tests should I perform next?  I want to try my usual evening runs, where the humidity isn't as bad.  I should probably try a slower jog from the beginning without all those faster pace tests at the start.  What would YOU suggest I try?  Should I just give up?


  1. Such a pain! For what its worth, what I've heard both in class and in my reading is that in addition to the heart rate rule there are two other rules. 1. You should be able to hold a conversation while you are running, and 2. If you were running a lot before pregnancy (which obviously you were) then maintaining that level of activity, perhaps slightly decreased, should be fine.

    So if while your heart rate is around 160 you can still carry on a conversation, seems like you could be good to go. Hope you are able to come to a conclusion that both you and your doctor are happy with!

  2. Ok- a few thoughts. I certainly don't want to disagree with your doctor- he/she knows best....but it is my understanding that the 140 HR is kind of "old school". (here's a quote from an article:
    “One of the keys is whether a woman exercised before her pregnancy,” says Burke. “If she exercised at 70 percent of her maximum heart rate (age subtracted from 220 times .70) before she became pregnant, she might be able to continue at that rate even if that number is above the 140 beats per minute (bpm) benchmark that has been established for pregnancy. Otherwise, she should keep her heart rate below 140 bpm at all times during her pregnancy. The Polar monitor will help her follow her doctors recommendation.”

    That being said- I think the effects of the heat are what you need to be concerned about...your core body temperature is already elevated because of the baby, you may tend to be a bit consider doing the test inside on a treadmill or at a cooler time of day. Stay hydrated and cool because those things cause everyones HR to be elevated.
    Runner's World has a pretty good book about Running in Pregnancy- you might want to check it out.
    If it continues to stay higher- you might even consider water running (although in my opinion it is about as fun as watching grass grow).
    Try it inside and see what happens.

  3. Wow, Libby, that does sound frustrating. My first thought was "how does that compare to your pre-pregnancy running heart rates, but seeing as how you ran with a borrowed monitor, I was figuring you likely wouldn't know. I own a HR monitor that I never use, so no just sucks.

    Maybe try it on a treadmill in an air-conditioned gym? Lord knows it not close to the same, but I'm guessing the bike and swimming will be friendlier. Better luck with your Doc next time.

  4. Don't give up, I find it hard to believe that every running pregnant woman kept her heart rate under 140. You were a runner before, I say keep researching. Good luck.

  5. The 140 heart rate is very old school. New recommendations use 'perceived exertion'. 140 is very arbitrary and feels different to each person. You might want to get a second opinion. I have been through training with experts on prenatal fitness and there is no reason why you shouldn't be able to run with a healthy pregnancy. I have some articles that I can send you when I get home (I'm commenting from my phone )

    Don't get discouraged. You will be able to get through this and have a wonderful prize at the end

  6. Not sure when you did your test, but today was HOT. I couldn't keep my heart rate at/under 140 today unless I was walking (and I'm not pregnant :-P). Granted, the Texas summer is only going to get hotter, but the heat definitely increases your level of exertion.

  7. Courtney RidingsJune 7, 2010 at 10:55 AM

    I know no one wants to use the dreadmill (Paula's popular term for it) but I would try running on your treadmill with a fan blowing directly on you and test your heartrate. You may find that running outside is off limits but inside might be a different story.