Exercise during Pregnancy 

Dr Davenport’s research has focused on the role of physical activity during pregnancy and post-partum period. You can see more of her work at www.exerciseinpregnancy.ca 

The 2019 Canadian Guideline for Physical Activity During Pregnancy was recently published in the British Journal of Sports Medicine. 

The last Canadian guidelines were published in 2003, and based on clinical experience rather than clinical evidence because the evidence just didn’t exist. This recent guideline has gathered evidence for the past 3 years from a broad representation of clinicians involved in the medical care of pregnant women.  

For this guideline, 12 systematic reviews were developed which included 37 outcomes including pregnancy, labour and delivery complications, maternal mental health and foetal growth and development.  

12 clinical guidelines exist internationally which focus specifically on exercise during pregnancy or in the post-partum period. Most recommend that if a woman has been previously fit and well, with no clinical contraindications to physical activity then it is safe for her to continue to exercise throughout her pregnancy.  

What are some of the contraindications to physical activity during pregnancy? 

Well, there are 2 types of contraindications to be aware of - absolute and relative.  

Absolute: women can continue normal activities of daily living but any more strenuous activity is not recommended. Examples of absolute contraindications include: being in pre-term labour, having preeclampsia or having a growth restricted baby. 

Relative: women are encouraged to speak with a health practitioner to determine the advantages and disadvantages to engaging in moderate to vigorous physical activity. Examples of relative contraindications are: Twin pregnancies after 28 weeks, gestational hypertension or recurrent miscarriage. 

Evidence gathered during the research for these guidelines showed that women who exercised during pregnancy were found to have a 40% lower risk of developing gestational diabetes and hypertension, preeclampsia, a substantial reduction in severity of depressive symptoms and reduced risk of having a very large baby. 

There was no increased risk of having a miscarriage, small baby or pre-term labour by exercising throughout pregnancy. 

The 2019 Canadian Guideline for Physical Activity During Pregnancy produced 6 recommendations based on evidence. They are as follows: 

  1. All women without contraindication should be physically active throughout their pregnancy

  2. Accumulate at least 150 mins of moderate physical activity per week. 

  3. These should be accumulated over at least 3 days a week, although daily physical activity is recommended. 

  4. Incorporate a variety of aerobic activities to achieve those 150 mins. Eg. Walking, swimming, stationary cycling, even doing housework. 

  5. Pelvic floor muscle training (kegals) should be included in pregnancy exercise routine. Evidence suggests up to 75% of women will develop urinary incontinence during their pregnancy, and these exercises can help to avoid this condition. The guidelines do suggest women should seek proper instruction from a professional to ensure they are performing these exercises with the correct technique. 

  6. Women who experience light headedness when performing exercises in a supine position should modify their exercise to be able to lie on their left side or raise their incline to 30% from supine.  

Is there such a thing as too much exercise during pregnancy? 

There is limited evidence available for the effects of physical activity / exercise above the recommended levels, for example including exercise such as High Intensity Training, challenging cardio exercise routines, or extended periods of training. This is an area that requires more work to identify if there is an upper limit to the amount of exercise a woman should be doing during pregnancy. 

Is there anything I can’t do? 

Some forms of exercise are not recommended during pregnancy – primarily those which have a greater risk of trauma to the belly such as horseback riding, cycling, skiing. Scuba diving is not recommended because there is no known safe depth for the foetus. It is also not recommended that women exercise at high altitude unless they were born in those environments. It is still recommended to avoid exercising in excessive heat due to the risk of dehydration and vasodilation increasing the risk of pregnant women fainting.  

There was no evidence to suggest that there was any risk of miscarriage if a woman exercises during the first trimester of pregnancy, and in fact these new guidelines do recommend that women do engage in regular exercise for 150 minutes over at least 3 days a week from conception until birth.  

If you have not exercised at all before becoming pregnant, it may not be possible for you to meet the guidelines suggested 150 minutes per week straight away. It is recommended you start with a gentle walking programme, building up by 5 minutes per week throughout your pregnancy, until you meet the recommended 150 minutes. You will still benefit from the exercise that you do fit in. 

Of course, remember....There will be times during pregnancy when you are likely to feel unwell or particularly tired. On these days it is absolutely ok to take a break, listen to your body, allow yourself proper time to rest and recover, and then return to the programme when you feel able to.

Emma Bradley