Is it safe to run during pregnacy?


A recent report commissioned by the International Olympic Committee explores the risk associated with competing in running events during pregnancy. 

Is it good for me or am I doing damage?


Norwegian long-distance runner, Ingrid Kristainsen, won the Houston Marathon whilst unknowingly pregnant in a time of two hours 33 minutes. Female athletes often have irregular menstrual cycles, so it’s not uncommon for them to become pregnant without knowing. Over the years, at least 17 women have competed at the Olympics pregnant.

As part of its commitment to women’s sport, the International Olympic Committee (IOC) recently called a group of experts to a meeting in Lausanne and asked them to write a report. Their review is being published in the British Journal of Sports Medicine. Despite the complexity of the material, the lead author’s message is simple.

“There are only a few high-quality studies into pregnancy among elite athletes or those who exercise a great deal, but it seems that many do continue to exercise during pregnancy, and it does not affect them in a negative way. It doesn’t seem to harm either the foetus or the mother.”

Professor Kari Bo, Norwegian School of Sports Sciences

These athletes are no more at risk of problematic pregnancies or birth defects. At the same time, there is no evidence that athletes have an easier time during pregnancy or childbirth.

Women who are athletic have very good blood distribution, so exercising doesn’t seem to do any harm to the foetus, and at the same time it’s obvious that the placenta is also better nourished when you are exercising, so there’s a sort of compensation going on.

Pregnant women have improved temperature regulation (which is why they may sweat more) and greater cardiovascular capacity. Hormonal changes may mean they feel more flexible in their joints, and an increase in the concentration of red blood cells means they can carry more oxygen around their bodies.

Studies indicate that elite athletes who train during and after pregnancy may see a 5-10% increase in their maximal oxygen consumption in the months after giving birth, though this was not observed in recreational athletes.

Rather than dispensing a list of technical do’s and don’ts, Bo has a simple message for pregnant women athletes: listen to your body. If you do something that feels wrong, it’s probably best to stop.

The new research fits with current advice for the general public. The American College of Obstetricians and Gynecologists recommends that pregnant women participate in aerobic and strength exercises, which may reduce the risk of diabetes and improve mental well-being. However, before women embark on an exercise program, they should seek medical advice.

In the UK, the NHS also advises women to continue exercising through pregnancy, though it says they shouldn’t work out so strenuously that they can’t hold a conversation at the same time. What counts as “strenuous exercise” clearly depends on how fit you are and how much sport you already do, says Prof Bo.

running during pregnancy

After childbirth, women are traditionally told to take it easy for the full postpartum period of six weeks, but Kari Bo says this is something of an arbitrary time period. In reality, athletes who have experienced a straightforward pregnancy and birth often start exercising after one or two weeks.

Back in 1983, Ingrid Kristiansen gave herself just four days of rest following the birth of her son before she began training once again. A month later she was taking part in cross-country competitions, and before too long came the Houston marathon, which she won with a time five-and-a-half minutes faster than the year before – 2:27:51.

But although the recent IOC-commissioned review is encouraging to athletes who wish to train through pregnancy, Kari Bo admits she often finds herself urging elite sportswomen to take it easier during pregnancy.

“I think women athletes are very, very afraid that they will lose their fitness,” she says.

“And to those women I say: ‘You do not lose a lot by moderately exercising for the last two months of your pregnancy. This is only a few months in your life, you know? So take care, because you have a passenger.'”


Take home message:

  • Listen to your body
  • Continue to follow you exercise routine, if you have never run do not introduce to your routine
  • Refrain from maximal efforts during endurance training
  • Reduce the weight you are lifting in strength sessions as it may increase blood pressure, stop blood flow to the foetus, and strain the pelvic floor
  • Scuba diving is not advisable during pregnancy
  • Women in their final trimester should avoid participating in sports such as football or hockey where they may have a fall or collision
  • Return to exercise at your own pace depending on the birth history. Begin with light exercise such as walking, yoga or swimming and re-introduce your routine slowly. Most of us are not Ingrid Kristiansen.

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