What You Need To Know About Exercise During Pregnancy

On my first baby, when I found out I was pregnant, I stopped running in my first trimester. Why? Because having experienced a miscarriage a few months beforehand, there was just something in the back of my mind thinking "God I wonder does all this running and bobbing up and down somehow affect this tiny baby's ability to grow and cling on to life? So in essence, fear stopped me, and I guess also a lack of knowledge. I kept walking all the time throughout and eating healthily, but looking back, I really wished I kept my fitness levels higher.

Fitness and supporting women on their journey into motherhood are both big passions of mine. So, I committed to learning more about it. Learning the facts, the guidelines, the safety aspects - I recently completed my qualification as a Prenatal & Postnatal Fitness Specialist, (I already hold pre/postnatal yoga, Hatha Yoga, and several other qualifications in the related field).

In a nutshell, the question everyone wants to know is: is it safe to exercise during an uncomplicated pregnancy? And yes is the answer! But you will probably get different answers depending on who you ask. Only very recently I met a pregnant lady who normally runs a lot and is very fit and healthy. I asked her was she running and she said no...but there was a lot of hesitation in her voice. She said that when discussing it with her consultant, he asked her 'well are you the type of person who would regret it if anything happened to your baby'?! So that was very reassuring...not. 

The old school advice was always a bit grey & muddy, with many consultants advising against continuing your exercise routine in pregnancy, as the thoughts were that people were unsure if in fact exercising was safe during pregnancy. However, in recent years there have been several studies showing positive outcomes for women, and their babies, who start, or continue to exercise during their pregnancy. 

An overall recommendation for exercise during pregnancy is this:

According to the American Congress of Obstetricians and Gynecologists (ACOG), if a woman has an uncomplicated pregnancy she should engage in aerobic and strength-conditioning exercises before, during and after pregnancy.  The American College of Sports Medicine (ACSM) suggests that 'moderate to hard' is quite safe for a woman who is accustomed to this level of exercise. 

Why is it important to exercise during pregnancy?

In western populations, there are more large-birth-weight babies (≥4.5kb – 10lbs) born now than low-birth-weight (<2.5kg – 5.5lb). The impact of being born in this higher spectrum is now becoming increasingly important for medical research – and the link to the obesity epidemic. A mother that is overweight or obese in pregnancy is more likely to deliver a ‘large’ baby. 

Continuing to exercise during pregnancy has many benefits for the mother:

  • Reduced risk of late pregnancy complications like preeclampsia, gestational diabetes
  • Regulates appropriate maternal weight gain (women who gain an excessive amount of weight during pregnancy tend to retain it postnatally, and therefore can lead to many future health problems)
  • Significant mental health benefits during and after pregnancy
  • In labour, the overall length doesn’t tend to decrease with women who exercise during pregnancy, but some studies show that the pushing phase (2nd stage) may be shorter in fitter women
  • In labour, fitter women require less medical interventions with fewer instances of fetal distress
  • Fitter women tend to have less c-section and instrumental deliveries: Dr. James Clapp conducted a recent study of physically fit women, and compared those who continued their exercise regime as per pre-pregnancy, against those who didn't maintain their aerobic fitness. He discovered that both C-section and instrumental deliveries were reduced in those who kept up their exercising regime.

                                  - Caesarean deliveries 6% v 30%

                                  - Instrumental vaginal deliveries 6% v 20%

When to start exercising during pregnancy?

According to the research, there is no reason for a woman to postpone an exercise program if her pregnancy is progressing well from the start, is uncomplicated, and she feels good. In fact, it is now recommended that every pregnant woman exercises in all trimesters, even if she has led a very sedentary lifestyle in the past and is overweight.  If you are not used to exercising, then you must start slowly. 

If you have been exercising regularly pre-pregnancy, then the research says, keep doing what you are doing as long as you are comfortable, and it's not part of the list of activities that you should not take part in while pregnant (see below).  There is no research indicating that exercising in the first trimester causes a miscarriage.  In general, women tend to feel better when they participate in low - moderate intensity exercise during the first trimester. 

How much should you do?

Here are the exercise guidelines based on Pre-Pregnancy Fitness Levels (for uncomplicated pregnancies with doctor’s permission to exercise):

  • Sedentary & Obese ladies: begin with short, low-intensity periods of exercise & gradually increase. Think of 10-15 minutes of continuous exercise per day x 3 days per week. You can increase from this once you are consistently achieving this level. Then see below for the next level. Walking / Swimming are both suitable activities for overweight people, as they minimize the chances of joint or muscle discomfort and stress.
  • Sedentary women: when starting a program, begin with 15 mins continuous walking, x 3 per week. As consistency continues, increase to 30 mins x 4 per week. Walking is preferable.
  • Somewhat Active women: (participating in exercise & activities x 3 per week in pre-pregnancy). Recommended 30 mins x 5 weekly sessions (or 150mins in total). Strength training can be introduced gradually. Brisk walking 5 times per week, plus short strength training days introduced gradually after 1-2 months.
  • Recreational Athletes: (women who habitually engage in exercise can and should continue their pre-pregnancy regimen, adjusted over time). Keep sessions below 45 mins to maintain adequate blood sugar levels.

For all pregnant women exercising, you should:

                          * Avoid overheating

                          * Maintain adequate calorie intake - eat a small meal containing complex carbs,

                              some protein and fat, 1 hour before exercise

                          * Maintain weight gain as recommended by medical practitioner

                          * Maintain proper hydration – drinking every 15 mins during exercise, and increase 

                            water uptake throughout the day

                          * Beware of injuries – balance challenges, joint laxity

                          * Refrain from getting overtired

                          * Perform thorough warm up and cool down

                          * Know when to adjust your routine

How do I know if I am doing 'too much':

You need to ensure you are feeling comfortable at all times while exercising, and follow the above guidelines. At no time should you feel pain, cramping, or feel lightheaded. If any of these occur, you stop immediately. If there is ever any pain accompanied by vaginal bleeding, you must go to your doctor or hospital as soon as possible. A guideline for a concerned mother in mid-late pregnancy to follow is that the baby should move two to three times in that half hour of cooling down. When a woman exercises only to find an absence of kicking for 30 minutes after a workout, she must see her doctor as soon as possible. Wearing a heart rate monitor is NOT recommended during pregnancy, as the heart rate naturally elevates. So another way to monitor how hard you are working is the 'Rate of Perceived Exertion' (RPE). This is a scale from 1-10, describing the intensity while exercising. You should also use the Talk Test - if you cannot speak a full sentence while exercising, the intensity is too high for you.

The American Council on Exercise suggests a level of 5-8 RPE. The  American College of Sports Medicine recommends a level of 3-7. So let's take the middle of both recommendations of exercising between levels 5-7.

Here is how the levels are described:

5.     Feeling you get when rushing out the door

6.     Feeling you get when rushing up the stairs

7.     Exercise while singing

According to Dr. James Clapp (2012), women who exercise right up until their due dates gain the most benefit. Amazingly, from a study of placenta growth in exercising and non-exercising pregnant women: 

When women continued their aerobic activities until delivery, their placentas grew nearly a third faster in mid-pregnancy and gained approximately 15% more blood vessels and surface area at term.

What are the best types of exercises to do?

You want to think about keeping yourself steady, feeling safe, and also preventing any potential trauma to baby.  Walking, stationary cycling, swimming or aquaerobics are all great aerobic examples of these. Modified running and strength training are also options which are approved as safe. Pilates and Yoga with qualified instructors will help to build strength and flexibility in the body, so as to minimize common aches and pains in the back, ribs and pelvis. 

Adaptations for each trimester:

In the first trimester, your blood pressure decreases and your heart is working a little harder - your heart rate at rest is up 15-20%. Therefore you may be prone to dizziness, a faster heart rate and that feeling of finding it hard to take a deep breath. Adapt your exercise regime to suits how your body is feeling.

Then the second trimester is generally when you feel you have most energy, so you should feel pretty well exercising during this time.

The final trimester is when your balance may feel a little off as your centre of gravity and posture tends to change. You might feel less steady and feel like you have a higher chance of falling over, so watch out for this during exercise, and minimise any chances of this happening by chosing suitable activities. You also might find your sleep is broken, so energy levels in general could be low at times. 

If you had been using weights for the lower body, it's unlikely you will need them now as your body has increased in weight.

Exercises to avoid:

  • Anything lying down on your back for long periods of time
  • Contact sports like soccer, hockey, basketball
  • Activities with a threat of falling or injury like horseriding, skiing, squash
  • Any form of heated activities like hot yoga, or hot pilates
  • Activities which require constant repetition, heavy lifting or any activity that requires straining, should not be performed.

On that note, I wish you a very healthy and active pregnancy! I now offer an Online Prenatal Yoga course that you can take at any stage of your Pregnancy. There are 5 different sequences available to practice, depending on your needs. So if you want to practice yoga during your pregnancy (which obviously I highly recommend!!) and have me at home with you (you lucky duck;-) ), then click here for my Prenatal Yoga Online Course

If you'd like to find out more about my full Own Your Birth online yoga & birth preparation course, which includes all the yoga from the online course, please click here. 

So to recap, if you have an uncomplicated pregnancy and have had clearance to exercise from your doctor, you should be exercising appropriately to your pre-pregnancy fitness levels throughout your whole pregnancy, as long as you feel well. We now know that is is safe, but also recommended for the health of the mother and of the baby, as long as you are sticking to the guidelines. 

Helen Plass is a Pre & Postnatal Fitness Specialist, and Yoga Instructor, working with women and their birthing partners to achieve a comfortable, healthy & happy journey into Pregnancy, birth and Motherhood. She is known for her very practical & non-judgmental approach to pregnancy and the crazy times of motherhood. Check out all her communication at NurtureMamas.com, and if you are in Ireland, her local business MumandBaby.ie