5 Myths of Exercise during pregnancy busted.

Let’s get a few things straight around pregnancy and exercise.

For many women, exercise during pregnancy is not only safe, but it is also recommended. According to the 2019 Canadian Guidelines for Physical Activity During Pregnancy,

“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. Physical activity should be accumulated over a minimum of three days per week; however, being active every day is encouraged”

Whilst knowing that you should be exercising is one thing, it is another thing to sort the fact from the fiction – or at least the outdated information.

Let’s look at 5 of the most common things women hear about exercise during pregnancy.

1. Don’t start anything new

It has often been said that pregnancy is not the time to try anything new when it comes to exercise.

Let’s apply a little common sense here.

Sure, if you have never lifted heavy weights before, jumping straight in doesn’t make any sense. But it doesn’t make sense whether you are pregnant or not.

Given the guidelines suggest regular physical activity during pregnancy, for some women this will mean starting something new. That might be starting out with small bouts of walking and increasing the length of your walks – this is something new that makes sense.

Or it could be working with a qualified prenatal trainer to start doing resistance or strength training.

Many women find that they are drawn to different activities when pregnant – yoga, pilates, and swimming all tend to be very popular. Just because you have never done these before, pregnancy is not a reason to exclude them.

The key is to start slowly and at a lower intensity and gradually build up from there.

2. Don’t exercise during the first trimester

This one links to the higher rate of the risk of miscarriage in the first trimester, compared to later trimesters. The risk of miscarriage decreases as the weeks progress, with a drop from about 7 weeks and then a substantial decrease from 14 weeks. From 14 weeks onwards the risk of miscarriage is less than 1%.

According to one study, there are many factors that may link to miscarriage including,

‘High maternal age; previous miscarriage, termination, and infertility, assisted conception; low pre-pregnancy body mass index; regular or high alcohol consumption; feeling stressed (including trend with the number of stressful or traumatic events); high paternal age and changing partner’

Notice, there is no mention of exercise.  This study showed there was no association between strenuous exercise and miscarriage.

Some women may find that exercising during those early weeks of pregnancy helps relieve symptoms like morning sickness. And with a link between exercising and feeling good, perhaps it is a good way to stay positive. 

3. Don’t let your heart rate go above 140 bpm

This was part of the guidelines when I first studied to be a personal trainer, some 10 or so years ago. And you still often hear it said today.

But is it accurate?

There are a couple of issues with using heart rate as the best way to measure how hard you are working

Your heart rate is like to be higher during pregnancy. So you may feel like you aren’t working any harder than normal but your heart raight suggest otherwise.

In certain situations, it may be hard to track your heart rate and relies on you having a heart rate monitor.

There is no mention of keeping under 140 bpm in the Sports Medicine Australia Guidelines, updated in 2016. Nor is it in the American College of Obstetricians and Gynecologists (ACOG) guidelines from 2015 (reaffirmed in 2017). ACOG says ‘the use of ratings of perceived exertion may be a more effective means to monitor exercise intensity during pregnancy than heart-rate’.

So what does that mean?

Perceived rate of exertion refers to how hard you feel like you are working. There are many ways of referring to this, most of them based on the Borg Rate of Perceived Exertion (RPE) Scale. It comes down to how you are feeling and how hard you feel like you are working. During pregnancy, it is  recommended that you work out at a moderate intensity. Moderate intensity would be 12-14 on Borg’s scale of 6-20. or 4-6 on a scale of 1 -10 (like the one below). In other words, you should be able to have a conversation but not sing. So busting out your favourite number whilst exercising will have to wait.

 Rate of Perceived Effort Scale 

4. Don’t exercise whilst lying on your back

I mention this one, not because it is a myth per se, but because there is so much conflicting information about when and how it applies. It is important to understand the reason why this one is talked about. Due to the weight of your baby, lying on your back (supine position) may restrict blood flow in one of the major vessels and cause nausea and dizziness.

Some guidelines recommend not doing any exercise lying on your back after 20 weeks. Others recommend not doing any prolonged exercise whilst lying on your back (without necessarily qualifying what counts as prolonged). Sports Medicine Australia recommend not exercising on your back after 28 weeks.

Whichever guidelines you choose to follow, it is important to watch out for any caution signs. If you start feeling any dizziness, nausea or light-headedness whilst lying on your back, change positions. Perhaps try rolling slightly onto one side, propped up by a towel, mat or pillow if it helps, or using a fitball to be on more of an incline.

5. Pregnancy is a time for putting your feet up – not exercising.

Putting your feet up at the end of a long day is always appealing. Especially when those feet are the swollen, tired ones of a mum-to-be. And there is definitely a time for relaxing, and it is important to listen to your body on this. But on the whole, exercising and remaining physically active is important.

Pregnancy is not a disease. In the absence of contraindications (click here to read more on this), being pregnant is not a reason in itself, to stop exercising.

In fact, there are a whole host of reasons for exercising including;

• Improved postpartum recovery time
• Decreased risk and severity of low back pain
• Helps prevent excessive weight gain during pregnancy
• Reduces  the risk of gestational diabetes
• Prevents/ improves symptoms of depression
• Maintaining, or improving, physical fitness
• Helping you prepare for the demands of parenting
• May reduce the risk of caesarean

So, as long as there are no health concerns, the recommendation is to keep moving. This includes aerobic and strength conditioning with yoga or pilates also being beneficial. Just keep moving.

The other reason to not follow the advice and put your feet up, has to do with optimising baby’s position. When you recline with your feet up, you have gravity working against you. One of baby’s heaviest body parts is their spine. When you are putting your feet up your baby’s spine will gravitate (quite literally) towards your spine. This encourages them to be in more of a posterior position.

So, spend time each day in an upright or forward leaning position. Exercises like cat-cow, bird-dog (anything where you are on all fours), squats or exercises done on a fitball may all help. Be mindful of how you are sitting. Make sure you are sitting upright or try straddling the chair for something a bit different.

So there you have it. 5 myths of exercising busted – or at least demystified.

To answer the question of ‘Can I exercise during pregnancy?’.

As long there are no contraindications to exercise (which you can read more about here), it is generally considered safe and beneficial to, exercise during pregnancy. Pregnancy in itself is not a reason to stop exercising, in fact, it might be a great time to start!

Your best bet is to work with a suitably qualified pre- and postnatal trainer or attend specific pregnancy exercise classes. Bright Mums and Bumps pregnancy exercise classes are evidence-based and are designed specifically for pregnancy. We focus on movements that will help support your changing body, are pelvic-floor friendly and prepare you for the demands of pregnancy, labour, and birth.

To find out more about Bright Mums Pregnancy Exercise Classes, click here