The Race to Conceive

Exercise and Fertility


Susan's working on number two. She's a runner. I've written about this breed before. Just a few weeks ago Kelly, another runner, was having problems with first trimester spotting and despite her dedication to keeping her baby safe, not running was driving her nuts. My husband's a runner too. Personally, I don't have the runner-thing going on but having lived with one for a long time, I get it. They have to run. Like I have to drink coffee and wear mascara; like kids have to play, birds have to twitter and dogs have to chew bones. They have to. They just have to.

Susan's only been trying to conceive for a couple of months but she's worried that running will interfere with her fertility. With all my ranting and raving about exercise and diet, she's probably confused about how much is enough and how much is too much exercise. First of all, let me say how happy I am to hear you're staying fit in preparation for another healthy pregnancy. It's the best thing you can do for yourself. Susan's questions are really twofold: 1) how long should you try to conceive before you get worried and 2) will exercise affect her fertility?

The official word on infertility is this: If you've been trying pretty diligently for a year with no luck; you've been at it for 6 months and you're over 35; or you've had multiple miscarriages, it's time to see a specialist. Two months with no pregnancy? Don't worry about it. Either your timing's a little off or your body's a little off. For whatever reason, most women don't get pregnant as soon as they throw out the birth control.

Now, about that running. Turns out they've done studies and yes, excessive exercise can interfere with getting pregnant. That said, what's excessive for one person isn't excessive for another. One study, published in the Oct. 2006 journal, Obstetrics & Gynecology, pertains specifically to women who are getting infertility treatment. They found that women who exercised four or more hours per week, and had done so for the previous one to nine years, were 40 percent less likely to have a baby after their first In Vitro Fertilization treatment than if they hadn't exercised. Surprisingly, however, women who had followed a rigorous fitness regimen for 10 to 30 years were just as likely to end up with a baby as women who didn't exercise.

So how does that translate to women who aren't seeking infertility treatment but still exercise a lot? It's not entirely clear because every body is so unique. It seems, however, that some women can exercise so much their body protects itself from pregnancy. It's as if the body figures it's already got enough going on and doesn't need any further challenges. There may be hormonal fluctuations that prevent conception or implantation. Some women have so little body fat their hormones levels run haywire and they don't menstruate or ovulate. If there's no ovulation, there's no chance of a baby. Susan says she menstruates regularly and runs between 3 and 10 miles per day. Is that too much? Who knows? My advice would be to keep doing what you're doing for a couple more months and if you're still not pregnant, cut back a little on the running and see what happens. If you're under 35 and still not pregnant in a year, go to your OB/GYN for evaluation.

Susan, you might want to consider a home ovulation predictor kit. It's a pee-on-a-stick thing that picks up Luteinizing hormone which increases at the time of ovulation. It might help you know more specifically when to "do it." Since you've gotten pregnant before, I have little doubt you can do it again. I have a friend who's a yoga instructor, thin as a whip and serious about getting pregnant. She didn't have any luck conceiving while teaching and practicing 3 hours of yoga per day. She cut back the number of workout hours, started eating more and voila, she's pregnant.

I think, sometimes, we just have to wait for the right baby to be ready to come into our life. You might be ready for your baby but maybe your baby needs a little more time getting ready for you. Obviously, that's just my new-age take on it. There's hardly a parent around who wouldn't agree that theirs is the perfect baby for them. Maybe we just have to wait for the right one to come along. Good things take time. Good luck, Susan. I hope you're pregnant soon and enjoy the process.

Got a question for Jeanne? E-mail it to and it may be answered in a future blog post.

This Fit Pregnancy blog is intended for educational purposes only. It is not intended to replace medical advice from your physician. Before initiating any exercise program, diet or treatment provided by Fit Pregnancy, you should seek medical advice from your primary caregiver.