Pregnancy and Running: What You Need to Know

Exercising when you’re expecting is safe, and experts encourage it.

You’re growing a tiny human inside of you and you feel enormous, exhausted, nauseous and like you need to pee every five minutes. Should you lace up or rest up? How will pregnancy affect your running? Will running affect your pregnancy? Here’s what you might expect from running when you’re expecting.

Reasons to Run

Exercise throughout pregnancy – at least 20 to 30 minutes a day on most or all days – is recommended. It reduces the risk of gestational diabetes, preterm birth, preeclampsia (pregnancy-induced high blood pressure), having a high birth weight baby, and the need for a cesarean section. It may also improve the baby’s brain development.

Plus, as any runner knows, it can make you feel better and relieve anxiety – over carrying and caring for a new baby, perhaps.

And despite some rumours, it won’t put you into labour, although it can help get you through it. “Women who exercise [during pregnancy] have easier, faster labors, they feel better postpartum, and their recovery is much quicker,” says Erin Dawson, an obstetrician-gynaecologist and runner.

But if you weren’t a runner before getting pregnant, it can be a challenging time to start. “There are so many body changes, your centre of gravity is off, it doesn’t feel that good,” Dawson says. She recommends starting with strength building and getting cardio from the elliptical or stair climber first.

Safety Concerns

If complications in your pregnancy arise – such as bleeding, placental problems, or preeclampsia – running can be risky. Having multiples might also put you at risk for premature labour and make running a no-go.

But for those with uncomplicated pregnancies, experts say there’s no harm in maintaining your exercise routine; running won’t cause miscarriage or hurt the baby. “The baby is pretty isolated and protected during pregnancy,” Dawson says.

You may start sweating earlier and faster, so be sure to hydrate well and wear loose fitting clothing. It may be best to move indoors on hot or humid days, particularly in the first trimester when a high body temperature (above 38°C) may cause neural tube defects, although it’s unlikely exercise will increase body temperature to a dangerous level. Hot yoga, hot tubs and saunas should be avoided, however, because they can quickly raise your body temperature.

Be careful on uneven surfaces as your centre of gravity changes. Concentrate on good form if you’re strength training. The body produces the hormone relaxin, which loosens ligaments during pregnancy. Relaxin acts all over the body but has its most profound effects in the pelvis (to loosen it, so the baby can make its way out). Loose ligaments can cause pain in the pelvis, sacroiliac joint, or lower back and make you feel extra sore after a run. And you can be more prone to injury, because looser ligaments aren’t as stabilizing.

There’s no need to monitor your heart rate. Go by perceived exertion and keep a conversational pace. “If you can talk and feel okay, you can continue,” Dawson says.

Making Adjustments

Accept that your running will change. “You’re going to get slower and that’s a given,” says Julie Levitt, an OB/GYN and marathoner. “But you may be able to spend the same amount of time active, you just won’t cover as much ground.”

Remember that this is not the time to push yourself: slow down, add walk breaks, or take extra recovery days as needed. “Give yourself some grace,” says Lindsey Hein, a mother of three. “Don’t hold yourself to a certain standard. Get started, see how it feels, and go from there.”

You’ll maintain fitness even if you cut back, as your body is working plenty hard on its own – boosting both blood volume and heart capacity. “You’re kind of getting super fit for your baby,” says Nadya Swedan, a physical medicine and rehabilitation specialist and author of The Active Woman’s Health and Fitness Handbook. “If you do half of what you were doing before, you’re probably going to end up at the same level of fitness when it’s all over.”

Thanks to increased pressure on your bladder, you may need to find new routes with places to stop and pee. Just don’t try to avoid bathroom breaks by cutting back on fluids; proper hydration is a must for the health of you and your growing baby. You may need more water than usual, but “if your urine is clear, you’re drowning,” Levitt says. “Go for the pale yellow colour and the feeling of satiation.”

Eat easily digestible carbohydrates before running, but give yourself extra time after eating before running because digestion may slow down in pregnancy. When you return, replenish with protein and electrolytes.

Running Through the Trimesters

For some, the first trimester is the hardest, thanks to the nausea and exhaustion. Both Dawson and Levitt say that running may help you feel better, if you can talk yourself into going. Of course, if you haven’t been able to keep any food down, it’s probably best not to run, Swedan says.

But the second trimester can be the ‘pregnancy honeymoon’, as nausea subsides and energy returns. After minimal running in the first trimester, Lindsay O’Brien, a former All-American athlete at Yale University who had her first child in September, increased her mileage in the second.

Still, as the body stretches and ligaments loosen to accommodate the growing baby, there may be some new pains. You may experience sacroiliac pain – pain in the lower back that may radiate down one side – or round ligament pain – a sharp pain or dull ache in the lower abdomen. Having a strong core can prevent or lessen sacroiliac pain and a belly band may help with round ligament pain.

When the third trimester hits, many runners find they need to stop. “The first week of my third trimester, everything stopped running wise,” O’Brien says. She had completed an 11K run a few days earlier but suddenly couldn’t run at all due to back and pelvic pain.

In her first two pregnancies, Roxanne Lorenz, a mother of three, got to a point where she just didn’t have the desire to run anymore. “Mentally, I was ready to be done,” she says. A 2015 study of 110 competitive runners found that only 31 per cent ran during their third trimesters.

But there are exceptions. In 2014, Lorenz started a running streak and didn’t break it during her third pregnancy. Eliza Miron, a streaker for over 14 years, also ran through her pregnancy. To keep their streaks, both had to run at least one kilometre every day – including the day of delivery and the day after. Miron, who gave birth at home, did a slow jog five hours later with her husband at her side. Lorenz ran very slowly on a treadmill the morning she went into labour, delivered that afternoon, and ran laps around her hospital room the next evening.

Both have run through injuries and illnesses, but were willing to give up their streak if any complications arose or a cesarean section was necessary. “Obviously if it didn’t work out, I’d rather have a healthy baby than make sure I got in my run,” Miron says. They don’t recommend such a strict regimen for non-streaking runners; neither got the approval from their doctor.

For the rest of us, Hein offers the more forgiving outlook she’s gained after running through multiple pregnancies. “By the time I got to my third pregnancy I was just like, ‘Let it go.’ If you feel good and you want to run, go run, and if you don’t, don’t.”

O’Brien agrees and says to not put too much pressure on yourself. “I figured if I sweat everyday or got in a little bit of activity every day it’s good for me and it’s good for the baby…even if it’s 10 minutes around the neighborhood or a little spin on the stationary bike.”

Returning to Running Postpartum

After your bundle of joy arrives, it may be weeks before you’re allowed to run. Although some experts say returning sooner may be okay, others recommend waiting to get cleared at your six-week postpartum checkup. “Your tendons and ligaments do remain a little bit relaxed and a little bit soft and injury prone until you’re further out,” Levitt says. If you feel good before that, go for a walk, try the elliptical, or do some light strength training.

If you want to work your core, Swedan suggests doing five minutes of planks and bridges every day rather than longer sessions less often. But Dawson says not to stress about it. “Lifting the car seat with the baby in it takes a fair amount of core strength – a lot of twisting, a lot of oblique work – so just having a baby is pretty good exercise,” she says. But for issues like diastasis recti (abdominal separation) or urinary incontinence, see a specialist for recommendations and exercises to do.

Be patient and don’t expect too much too soon. Like coming back from an injury, you’ll need to slowly build back up. “Take it easy on yourself. There’s so much going on, hormones and demands on your body,” O’Brien says. “I feel like running should be the last thing on the mind of brand new mums.” Not only has your body been through a lot, you’re probably not sleeping and breastfeeding can sap your energy even more. If you nurse, make sure to stay hydrated, get enough calcium and vitamin D, and wear a supportive sports bra (possibly in a larger size) when exercising.

But when things do start clicking again, you might discover an extra edge you didn’t have pre-pregnancy. “I definitely feel a lot stronger from going through the whole pregnancy and delivery,” says Desirae Piccoli, a runner who gave birth last June. “My pain tolerance is a lot higher.” Hein set a marathon PB nine months after having her first child.

Lorenz has also gotten faster with each pregnancy. “I just keep thinking, ‘If I can make it through labour, I can make it through this race.’”

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