Pregnancy & Exercise
It is the topic that has many different opinions and viewpoints. Is it safe and beneficial to exercise during pregnancy? Well thankfully as it is a very important topic in healthcare, there is an abundance of scientific research where we can get recommendations from.
We have two committees who have come together and presented separate although overlapping guidelines based off the evidence available and their expert opinions. The American College of Obstetricians and Gynaecologists in 2020 listed their key recommendations, which can be seen below.
ACOG Committee Opinion 2020 – Full link in references
1) Uncomplicated pregnancies should be encouraged to engage in aerobic and strength conditioning exercise before, during and after pregnancy.
2) A thorough clinical examination should be conducted before recommending an exercise program to ensure that a patient does not have a medical reason to avoid exercise.
3) Obstetrician-gynaecologist and other care providers should evaluate women with medical or obstetric complication carefully before making recommendations on physical activity participation during pregnancy. Activity restriction should not be prescribed routinely as a treatment to reduce preterm birth.
4) Physical activity and exercise in pregnancy are associated with minimal risks and have been shown to benefit most women although some modifications to exercise routines may be necessary because of normal anatomic and physiologic changes and fetal requirements.
5) Additional research is needed to study the effects of exercise on pregnancy specific conditions and outcomes and to clarify further effective behavioural counselling methods and the optimal type, frequency and intensity of exercise.
In 2019, a committee from Canada provided their own key recommendations from the available scientific evidence. The guidelines were reviewed by the Society of Obstetricians and Gynaecologists of Canada’s Maternal Fetal Medicine. Their key recommendations can be seen below.
Canadian Guidelines for Physical Activity Throughout Pregnancy, 2019 – Full link in references
1. All women without contraindications should be physically active throughout pregnancy.
2. Pregnant women should accumulate at least 150 minutes of moderate intensity physical activity each week to achieve clinically meaningful health benefits and reductions in pregnancy complications.
3. Physical activity should be accumulated over a minimum of 3 days per week, however being active every day is encouraged.
4. Pregnant women should incorporate a variety of aerobic and resistance training activities to achieve greater benefits. Adding yoga and gentle stretching may also be beneficial.
5. Pelvic floor muscle training may be performed on a daily basis to reduce the risk of urinary incontinence. Instruction on the proper technique is recommended to obtain optimal benefits.
6. Pregnant women who experience light headedness, nausea or feel unwell when they exercise flat on their back should modify their exercise position to avoid the supine position.
So how many women are getting the recommended level of physical activity whilst pregnant? Unfortunately, data from different populations show that this is a major concern! In 2004, Evenson found that only 15.8% in the United States were engaging in the recommended levels. In 2007, Domingues found that in Brazil it was as low as 4.7%! Whilst a more recent study in 2011 by Walsh found that in Ireland, only 21.5% met the recommendations. It would be interesting to know what percent of Australian women are meeting the recommended levels. To my knowledge I cannot find research investigating this.
From the data presented above, we need to do better in our education and prescriptions around encouraging women to engage in physical activity during pregnancy. This is what this blog is about. Awareness on this important topic will go a long way for the health of the mother and offspring.
“Pregnancy is a unique period of a woman’s life where lifestyle behaviours, including physical activity can significantly affect her health as well as that of her foetus.” Davenport 2018
Why is Exercise during Pregnancy so Important?
Exercise has a vast range of benefits to the overall health of those who complete it. Everyone should exercise for its effects on reducing the rates of disease development and improving functional capacity/quality of life.
With so many physiological changes to the woman during pregnancy, this arguably is more important than it ever was. You’re exercising for two as well as eating for two.
There are a few major symptoms/conditions we need to be aware of during pregnancy. They are something, fortunately, with exercise we can mitigate the risk of development!
· Pelvic Floor Dysfunction (PFD)
· Diastasis Rectus Abdominus
· Pre-eclampsia
· Gestational Hypertension
· Gestational Diabetes Mellitus
· Pelvic Girdle Pain & Low Back Pain
For a more detailed description of the above, please go to my Instagram account where I completed a 4-part series on Pregnancy & Exercise.
The Benefits of Exercising during Pregnancy
In the diagram below by Fahrenholtz in 2019, you can see that the benefits are plentiful and of real importance in reducing the development of the above conditions associated with pregnancy.
Getting back to exercise after birth has been shown to be quicker and most likely easier in active pregnant women! Research shows the postnatal recovery in active pregnant women is quicker (Price et al, 2012) and in those who continued to run during pregnancy, increased the odds that they will return to running postpartum (Moore et al, 2021).
Exercise also was found to reduce the odds of macrosomia, without increasing the odds of adverse outcomes. Therefore, exercise was found to also not increase the odds of pre-term birth, miscarriage, low birth weight and perinatal mortality (Davenport, 2018). This research paper also found that when 150 minutes of the recommended levels were met, there was a clinically associated reduction in the development of gestational diabetes, pre-eclampsia and gestational hypertension. When more physical activity over the week was completed, there was an associated benefit. When it came to the intensity level of the exercise, it was found that increased levels of intensity resulted in greater benefits.
Pelvic floor training should be an essential component of training for women. Women who have urinary incontinence have a reduced prevalence up to one year after delivery, when they trained the pelvic floor muscles (Haysmith, 2012). Whilst the research by Du in 2015, found that pelvic floor muscle training reduced the length of both the first and second stages of labour. Without a negative influence on childbirth!
What are the major considerations with Exercise and Pregnancy?
Firstly, follow the guidelines and speak to your obstetrician and gynaecological team. They will examine you and ensure you have no contraindications stopping you from exercising whilst pregnant.
Vigorous Intensity
Exercising at higher intensities imparts greater benefits, however what about vigorous intensity? Vigorous exercise is where you are training at 70% or more of maximum heart rate. Research by Beetham (2019) found that it does not compromise birth outcomes for most low risk pregnancies in the third trimester. However, if foetus is at the lower end of the birth weight chart during the third trimester, then moderate intensity exercise is recommended. So always consult your obstetrician/gynaecologist. If heart rate is at or above 90% intensity, then at this stage of research it is recommended to avoid training at this level. We need more research on this topic to determine safety.
Altitude Training
ACOG 2020 guidelines recommend women who live at sea level can train up to 1800m. However, the Canadian Guidelines in 2019 recommend that women who live at sea level can train up to 2500m. More research is needed here clearly, however if not acclimatised then it is recommended to refrain from training at more than 2000m.
Supine Exercise
ACOG guidelines of 2020 state, “Maintaining a supine position during exercise after 20 weeks may result in decreased venous return due to aortocaval compression from the gravid uterus, leading to hypotension. This haemodynamic change should be considered when prescribing exercise modification in pregnancy.”
Canadian Guidelines 2019 state, “Pregnant women who experience light-headedness, nausea or feel unwell when they exercise supine should modify their exercise position,” (low quality evidence).
Research by Barakat in 2016 found no adverse effects with exercising in the supine position for 2 minutes at a time. So, the main takeaway and recommendation is that women listen to their bodies and if ever feeling unwell or lightheaded, then change positions to something comfortable.
Strength Training
There are so many benefits of including strength training into your program. When combined with aerobic exercise, it results in greater health benefits than aerobic training alone (Skow, 2018). Research by O’Connor in 2011 found there were large strength gains in healthy pregnant women who strength trained twice a week for 12 weeks! The major concerns with this type of training are that women avoid the Valsalva manoeuvre and modify the exercise if they are feeling strain or excessive fatigue.
Summary
Exercising during pregnancy is important and highly recommended from the clinical research and experts in the field. Always speak to your obstetrician before you begin exercising to ensure you can complete it safely. At The Reform Lab Osteopathy, we have the fantastic gym Project Reform which we work out of. Osteopath Jackson has completed additional education in this area, as can be seen from the blog. So, if you are wanting guidance on exercise whilst pregnant, we would take pleasure in being a small part of the amazing journey you are going through.
References