Pregnancy: Why running is good for mom and baby

I could see the flag marking 20 kilometres just a few metres ahead of me, meaning I only had 2 kilometres left to go in the Trail Run Manitoba Race. The leaders were far ahead of me, likely already finished. The only people around were two course sweepers, and off-season ski patrollers on mountain bikes who sat astride their bikes at the 20 kilometre mark.

"Everything going OK?" one asked as I stopped to walk a loop around the flag and head to the finish line.

"Only 2K to go and then I get to eat pancakes. I mean, isn't that every pregnant lady's dream?" I replied, taking a big drink from the water bottle in my hand.

"What! You're pregnant? You're sure you should be out here?" asked the second sweeper.

"This is my fourth half marathon this pregnancy. The worst thing is having to stop and pee all the time. Do you guys mind riding up ahead—I need a few minutes of privacy," I replied.

Read more: Are pregnant runners selfish?>

I'm pretty sure if they weren't experienced cyclists the men would have fallen off their mountain bikes when I told them I was pregnant (22 weeks, to be exact). But they rode ahead, granting me a much-needed bathroom break. When I finally plodded up behind them, the sweepers had regained their composure and we finished the rest of the race together, chatting about everything except for the fact that it looked like I had a watermelon hiding behind the race bib pinned to the front of my shirt.

That was nearly five years ago, and if the public's reaction to Olympic athlete Alysia Montano running a 800 metre track race while 34 weeks pregnant are any indication, expecting athletes still have a long way to go to show the world that exercise during pregnancy is safe and beneficial to mom and baby.

Twenty-eight year old Montano made headlines last week when she crossed the finish line at the US Track and Field Championships. After getting clearance from her doctor, Montano raced against the sports top women, finishing in a respectable 2:32.13 to cheering crowds and a standing ovation. Montano finished last, but running the 800 metres had less to do with placing than it did clearing up misconceptions about running during pregnancy.

"That took away any fear of what the outside world might think about a woman running during her pregnancy," she explained in an interview with ESPN. "What I found out mostly that exercising during pregnancy is actually much better for the mom and the baby."

Finding information about the safety and benefits of running with a bun in the oven was hard to find when I was pregnant with Gillian five years ago. Without guidelines, I turned to my OB/GYN for answers. Not one to mince words, she said I looked great, my baby was healthy and to tell anyone who told me to stop running to shove off. Plagued by anxiety and weight gain during my first pregnancy, running kept my weight and mood stable during my second pregnancy.

Ultrarunner and mother Robin Aston has a story similar to mine. A lifelong athlete, Ashton ran, walked and swam through two of her three pregnancies. Her two oldest daughters, Emma and Erin were 11 lb. 2oz and 9 lb. 14 oz respectively, were carried full-term. While pregnant with Erin in 2003, Aston participated in a research project out of the University of Western Ontario to study how exercising during pregnancy affects mothers and babies. Part of the research required Ashton to run on a treadmill at her maximum heart rate.

"The doctor doing the research kept asking 'are you there yet?' I hadn't hit my maximum yet—which was 240 beats per minute!" says Aston.

In addition to measuring her heart rate, researchers also measured Ashton's lactate levels, oxygen levels and even took muscle biopsies. Study results confirmed what Ashton already believed—exercising while pregnant is great for mom and baby.

The widespread media attention surrounding Montano's US Track and Field Championship race is not unlike Amber Miller's 2011 running of the Chicago Marathon. Eight hours after crossing the finish line, Miller gave birth to her healthy 7 lb. 13 oz daughter. After publishing Miller's photo and story, the Chicago Tribune's website was flooded with readers criticizing Miller's decision to run the race, accusing the new mom of risking her baby's life. The Journal of Applied Physiology debunked the armchair athletes in the May 31, 2012 edition, saying that Miller's pace (not much faster than a brisk walk) combined with a sensible eating and drinking during the marathon is why she was able to successfully complete the entire 42 kilometre race. The handwringing about small birth weight babies or pregnant runners going into cardiac arrest while exercising is scientifically unfounded, said Gerald Zavorsky and Lawrence Longo in the Journal.

Until misconceptions about the powerful benefits of exercise during pregnancy are put to rest, join me in applauding inspirational athletes like Alysia Montano and Amber Miller.

Follow along as Jennifer Pinarski shares her experiences about giving up her big city job and lifestyle to live in rural Ontario with her husband, while staying home to raise their two young children. Read more Run-at-home mom posts or follow her @JenPinarski.