Running while Pregnant

by Cindy Hamilton, March ’03

If you run and are thinking about getting pregnant, I’ve got a book for you. Exercising Through Your Pregnancy is one of the few books I’ve read that not only supports running while pregnant, but advocates it.

Dr. Clapp states that you can train during

pregnancy and may even see an increase in

performance during the first trimester….

Please don’t be put off by the brightly clad woman on the front cover that is walking. This book is for serious runners (and other athletes) who are used to doing intense exercise and want to keep it up while pregnant.

I have read almost everything written on the subject of running while pregnant over the last five years. Some of what I read was helpful, but always superficial. And without a doubt, EXTREMELY cautious.

What is written tends to be trite as well. Yeah, yeah, take it easy, keep hydrated, watch for intense summer heat, and wear comfortable clothes… I know all this from normal running… what I wanted was more detail about how running was actually affecting the baby (and me) during my runs, and what were the long term effects of consistent running during gestation.

In Exercising Through Your Pregnancy, the author, Dr. James Clapp, III, M.D. starts off humorously by saying the doctors have the Don’t ask, don’t tell philosophy about exercise during pregnancy since there is such a lack of data. This is what spurred Dr. Clapp to study the effects of running while pregnant.

I had read that the blood supply to the fetus is reduced during intense (or long) running. What had really happened in my uterus while I ran 16 miles in my 7th month last pregnancy? And more importantly, did it adversely affect the baby I was carrying? I couldn’t believe that there was no biological provision that allowed for more intense exercise.

I was hungry for those details and Dr. Clapp provided them.

Especially interesting points:

  • Changes the women’s body goes through from exercising while pregnant either compensate for or complement the pregnancy and provide benefits to both the fetus and the mother. Example: exercising moms have larger placentas.
  • Dr. Clapp states that you can train during pregnancy and may even see an increase in performance during the first trimester over the nonpregnant state.
  • Consistent exercise actually creates a margin of safety for both mother and baby that could protect them should unanticipated medical problems arise in late pregnancy.
  • Regular exercise may actually decrease the chance of preterm labor (before the 36th week) and a low birth weight baby (<5.51 lbs.)
  • Exercising moms did produce babies that were slightly lighter (an average 7.2 lbs vs. nonexercising moms’ babies that are on average 8 lbs). Dr. Clapp argues that well developed babies are the goal and the exercising babies are just as developed, just not as fat.
  • The placenta of the exercising mom’s is larger than nonexercising mom’s. This is great except if you decide to stop exercising mid-pregnancy. Then you can count on the fattest baby of all three groups: exercising moms, nonexercising moms, and moms that exercised to the mid-way point. Moms that only exercised to the mid-way point had the largest babies of all since the larger placenta provides a marked increase in calories. Not a bonus when it comes time to get that baby out!
  • Women who exercise deliver their babies 5-7 days earlier than nonexercising. This is a benefit since the baby is fully developed and ready to come out.

The book dispels many misconceptions and covers many more interesting facts about exercise during preconception, how the baby progresses after birth, how running affects nursing, and includes all the normal warnings.

All in all, the most compelling book out there for runners who are planning a pregnancy. I wish I’d had it five years ago! Now I just need him to write a book on exercising while pregnant with TWINS—and fast!!