Exercise During Pregnancy Part 2: What about avid exercisers and elite athletes?

Exercise During Pregnancy Part 2: What about avid exercisers and elite athletes?

In the middle of October the Society of Obstetricians and Gynaecologists of Canada (SOGC) and The Canadian Society of Exercise Physiology (CSEP) released new exercise guidelines for pregnant women. The document demonstrates a significant change in how the experts in pre-natal health view exercise for pregnant women. In general the shift centres around the fact that exercise (a combination of aerobic and resistance training) is now specifically prescribed to the pre-natal population to reduce pregnancy complications and optimize health instead of it being just a recommended behaviour for pregnant women to engage in. Even for previously inactive women!

This was great timing for me, as at the time I was 15 weeks pregnant with my second child and thought it was a perfect reason to write a follow-up blog to our “Exercise During Pregnancy” post done a year ago. As an active person or “enthusiastic exerciser” I have done quite a bit of searching around for resources that involve pregnant women like me, so below I have put together a comparison summary of the new and old SOGC/CSEP guidelines and referenced some studies done with elite athletes or avid exercisers. I have also shared my experiences and what I am currently doing for exercise. Finally, I will be posting some of my workouts and experiences regularly on our other social media platforms (Facebook and Instagram), so follow along as I grow!

The new guidelines (and old ones for that matter) are for all women with exception to those who have absolute or relative contraindications.

Absolute contraindications to exercise are the following:

Relative contraindications to exercise are the following:

  • Ruptured membranes
  • Premature labour
  • Unexplained persistent vaginal bleeding
  • Placenta previa after 28 weeks’ gestation
  • Preeclampsia
  • Incompetent cervix
  •  Intrauterine growth restriction
  • High-order multiple pregnancy (e.g., triplets)
  •  Uncontrolled type 1 diabetes
  • Uncontrolled hypertension
  • Uncontrolled thyroid disease
  • Other serious cardiovascular, respiratory, or systemic disorder
  • Recurrent pregnancy loss
  • Gestational hypertension
  • A history of spontaneous preterm birth
  • Mild/moderate cardiovascular or respiratory disease
  • Symptomatic anemia
  • Malnutrition
  • Eating disorder
  • Twin pregnancy after the 28th week
  • Other significant medical conditions
Women who are experiencing any of these absolute contraindications, are recommended to continue their activities of daily living but to not add any more strenuous activity. Women who have relative contraindications are advised to speak with their obstetric care provider about implementing moderate-vigorous exercise before doing so.

It has been proven that exercising throughout pregnancy results in:
⁃ fewer newborn complications
⁃ lower number of Caesarean sections/instrumental deliveries
⁃ fewer cases of urinary incontinence
⁃ fewer cases of excessive weight gain
⁃ fewer cases of depression

Amazing!!

Now, let’s rewind just a couple of generations and think about how pregnant women were put in a padded bubble and told not to lift anything, move around too much and certainly not exercise! They were treated as though they had a serious health condition. Although our research has demonstrated the exact opposite and women today are generally much more active throughout pregnancy, only about 15% of pregnant women achieve the prescribed volume of exercise. Also, although it comes from a beautiful and caring place, even to this day others are overprotective when it comes to pregnant women. “Should you be lifting that in your condition?” , “Let me do that.”, “Just rest, that’s what you need.”. Certainly there are instances where this protection is necessary, but overall I think these statements come from generations of looking at pregnant women as people in an extremely fragile state.

If you would like to see all the details of the most recent SOGC/CSEP article, click here, but in a nutshell here is a little breakdown of the changes from the 2003 guidelines:

Topic New Guidelines Old Guidelines Notes
Pre-natal exercise Specifically prescribed Recommended
  • previously active women
Continue previous exercise regime with the goal of maintaining fitness (not to achieve peak performance). Continue previous exercise regime with the goal of maintaining fitness (not to achieve peak performance). With caution: that previously active women who participate in high risk activities such as contact sports or activities with a high risk of serious falls, modify activity.
  • previously inactive women
Gradually get to the recommended dosage of exercise and seek a fitness professional if they feel they need instruction or motivation.  Recommended dosage is stated below. Begin with 15 mins of continuous exercise 3 times/week and increase gradually to 30 minute sessions four times a week.
Prescribed volume 150 minutes/week over at least 3 days a week but everyday is encouraged. None given.
Prescribed intensity Moderate intensity 12-14 on the Borg Scale * See Borg Scale here
Intensity Levels Given or Recommended

  • given by heart rate (beats per minute)
<29 

Light = 102-124

Moderate = 125-146

Vigorous = 147-169

30+

Light = 101−120

Moderate = 121−141

Vigorous = 142−162

>20 = 140-155

20-29 = 135-150

30-39 = 130-145

40 + = 125-140

Studies on high-intensity exercise have not been done and therefore the affects on mother and fetus are not known.  It is recommended that if women wish to perform regular vigorous exercise that they consult their obstetrics provider.
Exercise Type Combination of aerobic and resistance exercise.  Yoga or gentle stretching may also be beneficial. Walking, stationary cycling, cross-country skiing, swimming, aqua-fit (minimal jostling and joint disturbances like running or jogging does)

Resistance exercise

*modes given, but nothing about the combination of aerobic and resistance exercise.

Studies have now shown that the combination of aerobic and resistance exercise during pregnancy was more effective at improving health benefits than aerobic exercise alone.
Kegels? Yes Yes

So…what does this all mean? In my opinion, despite the fact there are not countless large changes in the new guidelines, the changes that have occurred are incredibly significant and show an mindset change. I also believe the new guidelines provide pregnant women with specific and measurable goals to strive towards by stating a specific volume and intensity to achieve.

Ok, so what if you are an athlete or a very active women and you are surpassing the above guidelines? What are your boundaries? The International Olympic Committee (IOC) put out a research paper for this population.

Here is a little summary of just some of the topics covered. It is a very thorough paper; exploring a plethora of physiological, psychological and illnesses or conditions that come with elite sport. I have provided a summary of topics that surround a healthy pregnancy only, but if you are curious and wish to read more click here.

IOC Summary:
Active women and elite athletes often exceed the recommended amount of exercise outlined by the new guidelines and would like answers to questions like: How long? How frequent? How intense? And what type of activities are safe for mother and fetus? Also, how soon can they return to high intensity training or competition after childbirth?

Most of the recommendations are synonymous with the SOGC/CSEP recommendations, as there hasn’t been much research with elite or enthusiastic pregnant exercisers. But here are some of the findings:

Heart Rate:

  • Exercising at 90%+ of VO2max is not recommended.
    • Temporary fetal bradycardia has been demonstrated when mother exercises above 90% of max HR, but lasting effects on the delivered fetus is not known.
  • What can we use as a measure of training zones?
    • Not Rate of Preserved Exertion (RPE or the Borge Scale)
    • The Borg Scale is a simple way to estimate heart rate (HR) by multiplying your level of perceived exertion by 10, but it does not correlate strongly with HR during pregnancy. Actual mean HR is can be about 16 beats per minute higher in pregnant women than what the Borg Scale would state, therefore; the prediction significantly underestimates HR in pregnant women.

Weight Training:

  • Light to moderate weight training is now recommended and is actually good for women to do throughout pregnancy. In fact, significant strength gains have been reported in women who have started strength training during pregnancy. However, the loads/intensity used in these studies are far below those used by highly trained athletes.
  • Incorporating the valsalva maneuver during a heavy lift will lead to a large increase in blood pressure and intra-abdominal pressure (IAP), which, may decrease blood flow to the fetus.
  • Depending on how far along the athlete is and therefore, the relative anterior displacement of her abdomen and subsequent anterior rotation of her pelvis on her femurs, she may not be able to effectively create uniform IAP. This uneven IAP may have ill effects on pelvic floor support.
  • No studies have been done on intense strength training in pregnant women so we have very little knowledge in this area.

Altitude Training:

  • The IOC recommendations state that pregnant women can safely exercise at or below 2000m above sea level as there will be sufficient oxygen delivery to mother and baby.
  • The concern with exercising at higher altitudes is that the low air pressure found there reduces arterial oxygen saturation (the amount of oxygen our blood carries and delivers to our tissues).
  • The study indicates that some exercise tests were conducted on healthy women late in pregnancy at 6000m elevation with no ill effects on fetus, but there has not been any studies done on endurance athletes training at this level. It is therefore recommended that active pregnant women do not perform intense activity at altitudes higher than 2000m.
  • However! Check out this article recently posted in the N.Y. Times. It flirts with the notion that high intensity exercise is safe for pregnant women and references a couple studies done on pregnant elite athletes and extremely active pregnant women. One study was done on an elite runner who was a Sherpa in Nepal for trekkers visiting Mount Everest. She was 7 months pregnant and performed 270 mins of physical activity a day during an eight day trek to Mount Everest’s base camp! She had a healthy baby two months later with no complications. This was a singular case study and certainly not the norm, but perhaps it will open the door to finding more women like this of which we can study.

Ok, so what does this all mean? It is great that the new protocols prescribe exercise for relatively healthy pregnant women, that there are multiple heart rate ranges to work within and that there are now a variety of exercise modes that have found to be beneficial. However, for elite athletes or avid exercisers much is still unknown.

What to do? The safest option, and my recommendation is to follow the guidelines.

What am I doing…ok here goes…

My personal findings:

I seem to be doing more loading this pregnancy than last. I am therefore finding that I have to do a bit more work focusing on my positions and it feels like I am modifying my workouts more this time. My resistance training workouts require me to create stability in order to lift effectively. I find when I am required to lift heavier objects or generate more effort, my abdominal muscles protest slightly in the form of gentle cramping. I then back off and find a modification. For example, lately pull-ups create that sensation for me; however, if I try some in a flexed hip and knee position I do not cramp or if I use a light band for assistance I am able to keep a position that my abs like.

With respect to my training intensity and heart rate, I have been finding that running creates a spike in HR for me unlike any other workout (over spin class or circuit training). I have therefore paid particular attention to my heart rate via my watch when running. If my heart rate elevates past 85% of my heart rate max and stays there for more than a few moments, I slow my pace and recover slightly. I am still exercising in heart rate ranges that are above the SOGC/CSEP recommended levels. For my age group, 162 bpm is the top end of the vigorous HR scale and I find myself at 160-168 bpm quite regularly in my workouts. However, as I mentioned I modify my activity and intensity level so as not to stay in that range for long.

My thoughts for those who are avid exercisers and who wish to train during pregnancy:
a) Listen to your body – keep doing what feels good and stop what feels painful or wrong.
b) Wear a heart monitor for self monitoring.
c) If you want to continue with higher intensity training perhaps i) do a workout that allows for a good recovery between intense intervals (so you are not performing longer/sustained higher intensity work) and ii) inject long slow duration low intensity workouts between higher intensity workouts so you are not always working out at vigorous levels – which is actually good advise for all exercisers!

Michelle Meckling CAT(C), CSCS, BAET, BEd

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References:

New SOGC – Society of Obstetricians and Gynaecologists of Canada guidelines
https://els-jbs-prod cdn.literatumonline.com/pb/assets/raw/Health%20Advance/journals/jogc/JOGC908_LR-1539864964137.pdf
https://sogc.org/news-items/index.html?id=229

CSEP document – good outline of new guidelines:
http://csepguidelines.ca/wp-content/uploads/2018/10/4208_CSEP_Pregnancy_Guidelines_En_P2A.pdf

IOC – elite athletes/recreational athletes
https://bjsm.bmj.com/content/50/10/571
IOC summary:

NY Times – vigorous exercise during pregnancy

Borg Scale for Rate of Perceived Exertion
https://www.healthlinkbc.ca/physical-activity/borg-rating-perceived-exertion-scale

Reference to old guidelines:

Joint SOGC/CSEP Clinical Practice Guideline:
Exercise in Pregnancy and the Postpartum Period
— Principal Authors —
Gregory A.L. Davies, MD, FRCSC, Kingston ON
Larry A. Wolfe, PhD, FACSM, Kingston ON
Michelle F. Mottola, PhD, London ON
Catherine MacKinnon, MD, FRCSC, Brantford ON

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