If you are pregnant, thinking about becoming pregnant, or returning to exercise following pregnancy then we can help. Many pregnant women are concerned about the effects of exercising during pregnancy but the good news is that, for the vast majority of women, it is not only safe for the baby but good for you both! In this section we discuss how to exercise safely and what to look out for as a sign that you shouldn’t exercise. However, if you have any concerns, you should always talk to your doctor or midwife before starting to exercise.
1. What are the benefits of exercising during pregnancy?
For the woman…
For the baby…
Potentially less chance of the baby becoming distressed during delivery (though this has many different causes)
May help to enhance brain development during infancy
2. Is there anyone who shouldn’t exercise during their pregnancy?
Most pregnant women can exercise safely during pregnancy but there are a few conditions where it may be risky for the mother and/or the baby:
Significant heart or lung disease
Incompetent cervix (if you’ve had a history of recurrent late miscarriages then this can be the cause and you should talk to your doctor about whether you can keep exercising)
Persistent bleeding in the 2nd or 3rd trimester bleeding
Placenta praevia after 26wks (where the placenta is low lying and covers the exit from the womb)
Premature labour during current pregnancy
Pre-eclampsia/pregnancy induced high blood pressure
Multiple gestation (carrying twins or more) at risk of premature labour
Very low iron (haemoglobin less than 10)
Poorly controlled Type 1 diabetes
Being very overweight or underweight (BMI >40 or <12)
Being very sedentary prior to pregnancy
Restricted growth of the baby during current pregnancy
Poorly controlled high blood pressure
Severe back, pelvic or other joint pains
Poorly controlled epilepsy
Poorly controlled hyperthyroidism
Premature labour during previous pregnancy
This may seem like a long list of exceptions, but the number of pregnancies that are actually affected by one of these conditions is pretty low and they don’t always mean that you can’t do any exercise. However you’ll need specialist advice about what is or isn’t safe for you to do.
If you have been diagnosed with something on the list above or have any concerns about pregnancy-related symptoms then it is always best to speak to your doctor or midwife before starting to exercise.
3. Are the any risks to exercising during pregnancy?
Outside of the conditions listed in section 2, then there is no evidence that there is an increased risk of complications for the mother or the baby if the woman exercises during her pregnancy.
One concern that is often raised is about the risk to the baby if the pregnant women over heats (hyperthermia); for example if they have a high fever with an illness. During the first trimester in particular this can increase the risk of developmental problems in the baby (in particular spina bifida). There is no evidence that becoming slightly warm during exercise can cause this however the advice is always to make sure you don’t become uncomfortably warm during exercise and if you find yourself feeling a bit hot then stop and rest until your body temperature feels normal again. Drinking plenty of fluids during exercise will also help. Also, you shouldn’t exercise outside if it is a hot day and you shouldn’t do bikram yoga (a type of yoga done in a hot room).
4. Are there any signs I should look out for that mean I should stop exercising?
There are a few signs that mean you should stop exercising and get immediate advice from your midwife or doctor:
Chest pain or palpitations
Dizziness or feeling faint
Painful uterine contractions / preterm labour
Abdominal pain especially accompanied with back and/or pubic pain
Amniotic fluid leakage
Reduced foetal movement
Calf pain or swelling
If you experience any of these symptoms whilst you are exercising then you should speak to your midwife or doctor straight away.
5. What sort of exercise should I do and how much?
The recommendation from the Royal College of Obstetricians and Gynaecologists is that pregnant women should do 30 minutes of moderate intensity exercise most days of the week. ‘Moderate intensity’ exercise means that you can still talk and hold a conversation but your sentences will be shorter. If you are used to monitoring your heart rate during exercise, then this equates to 50% - 70% of your heart rate max. But unless you are used to training in this way there is no need to start monitoring your heart rate just because you are pregnant.
It’s good to do a variety of exercise that will include activities to raise your heart rate (cardio), improve your strength and work on your core muscles. For example:
Swimming / aqua aerobics (water temp not >32deg)
Jogging / running (if you’re used to doing these before you were pregnant and feel comfortable to continue)
Yoga / pilates
Gym and gym classes
Pelvic floor exercises
In general, if you are used to exercising, then you can continue what you usually do, provided you feel well enough (with a few exceptions, see section 6). As you progress into your second and third trimester then you’ll naturally need to reduce the intensity and impact of the exercise and some exercises may become more difficult to do (more of that in section 8).
If you are exercising with a trainer or in a class you should always tell the instructor that you are pregnant so they can show you any modifications to exercises that you might need.
6. Are there any sports I shouldn’t do if I’m pregnant?
Most of the activities that aren’t suitable during pregnancy relate to the risk of trauma to the abdomen and therefore the baby, for example:
Contact sports eg rugby, martial arts (unless practiced alone)
Sports where there is a risk of falling eg riding, skiing
Sports where there is a risk of being hit in the abdomen by equipment eg tennis, squash
Exercising at high altitude (>6000feet)
7. What if I haven’t been exercising regularly before I became pregnant?
If you aren’t used to doing much exercise before you became pregnant then it is still a good idea for you to start. If you are very unfit you should talk to your doctor first but otherwise going for walks is a good way to start.
Begin with 10 minute walks every other day and then build up to 30 minutes on most days. You should aim to be walking at a ‘moderate intensity’ which means you should feel slightly sweaty and breathless but you can still talk (though your sentences will be shorter). Once you are used to doing some walking on a regular basis you can start to do other types of exercise (see section 6).
8. How might my exercise need to be different now I’m pregnant?
There are a few specific things you need to be aware of during pregnancy:
During the first and third trimesters in particular your body produces a lot of a hormone called ‘relaxin’. This helps to soften the ligaments around the spine, hips and pelvis in preparation for delivery. Ligaments hold bones together but in order for the baby to pass through the birth canal the bones need to move slightly to make more space. This is completely normal but it does mean that the stability of the joints around your back and pelvis is not as good as when you aren’t pregnant so very slightly increasing your risk of injury. Making sure you include some stability type exercises will help to reduce this risk. A pilates class run by an instructor who is trained in advising pregnant women is a good place to start. Also, be aware that when you are stretching, the softening of your ligaments might allow you to stretch further than usual, so don’t push yourself to stretch beyond your normal pre-pregnancy ability.
As your bump starts to expand (as you progress through your second trimester) then it is not advisable to lie flat on your back. This is because the weight of the baby presses down on the big vein in your abdomen so it restricts blood flow back to your heart causing you to feel light headed and dizzy. This will in turn reduce blood flow to the baby. If you are used to doing exercises such as pilates, yoga and some free weights exercises which include lying on your back then you will need to modify these. Your instructor / trainer should be able to give you suitable adaptations (for example, lying more upright) or give you an alternative exercise to work the same muscles but in a different position. In addition, certain weight lifting techniques may need modifying as your bump expands as it will be in the way!
There may also be an increase in the curve in your lower back (‘lordosis’) as your bump grows. This, along with the increased weight which you are carrying, puts more strain on your joints, especially in the back and pelvis. You should make sure you include core and general strengthening exercises to help support your back and protect it from injury and as your pregnancy progresses you should reduce the amount of any weights that you are lifting.
The most important thing is to listen to your body. It if feels uncomfortable or painful it’s not the right exercise for your stage of pregnancy. For further advice talk to you trainer or class instructor, if you have one, or ask your midwife, physiotherapist or specialist.
9. What about exercising after the baby arrives?
Your hormone levels remain high for at least 4 to 6 weeks or longer after delivery meaning that your ligaments will still be soft and you will be more reliant on your muscles to maintain the stability of your joints. These effects may last longer if you are breast feeding. In addition you have the small matter of the birth itself to recover from, along with the joys and challenges of caring for your new born! For all these reasons there is no need to feel you have to rush back into exercise after you’ve given birth. Pelvic floor exercises are good to start as soon as possible (or restart, as hopefully you’ve been practicing them during your pregnancy as well). After that, walking is the best first step.
In general the advice is…
After an uncomplicated vaginal delivery (ie no forceps/suction, no tearing):
Walking and pelvic floor exercises as soon as you feel comfortable to start
Increase the walking gradually, eg 10 - 30 minutes a day, low to moderate intensity
After your 6 week check you can gradually start doing other activities – when you feel ready to
Complicated vaginal delivery / Caesarean-section:
Wait for 6 weeks and until you’ve had your check with the doctor before starting to build up your physical activity
Again, start with walking and continuing your pelvic floor exercises