Regular physical activity during pregnancy not only has health benefits but also helps to prepare the body for childbirth. However, it is important to modify or choose a suitable exercise program because pregnancy affects the body's response to exercise.

How often should I exercise during pregnancy?

You should try to be active every day of the week. Depending on how much exercise you did before your pregnancy, be sensible about the level of exercise that you do.

You don't need to exhaust yourself — a light to moderate exercise program should be the aim, but if you feel comfortable, you can do more intense exercise.

As a general rule, a light to moderate level should allow you to hold a conversation during the activity. The more intense the exercise, the harder it will be to talk.

For low to moderate exercise, aim for 2½ to 5 hours a week (30 to 60 minutes most days).

If you are comfortable doing more vigorous exercise, aim for 1¼ to 2½ hours a week (15 to 30 minutes most days).

You don’t have to do your daily exercise all at one time; you can break up your routine throughout the day.

As your pregnancy progresses, you may need to slow down. If in doubt, consult your maternity team.

What should I do if I didn’t exercise before I was pregnant?

If you weren't active before you got pregnant, don't suddenly take up strenuous exercise. If you start an exercise program, tell the instructor that you're pregnant and build up slowly. You could begin with no more than 15 minutes of continuous exercise, 3 times a week and increase this gradually to up to 2½ hours a week.

Remember that exercise doesn’t have to be strenuous to be beneficial — and any physical activity is better than none.

Talk to your doctor or midwife before you start doing any exercise so they can guide you to the best options that will work for you.

What type of exercises should I do?

Doing a combination of aerobic and strengthening exercises is beneficial when you are pregnant.

Aerobic activities — like walking, cycling, swimming or fitness classes — will help you improve your cardiorespiratory fitness (your ability to take in and use oxygen) and also help you avoid excess weight gain.

Strengthening exercises, like yoga, Pilates or resistance training, can help to reduce back and pelvic pain and also help to prepare your body for giving birth, as well as your recovery after.

Try to fit the exercises listed below into your daily routine. They will strengthen your muscles so that you can carry the extra weight of pregnancy. They'll also make joints stronger, improve circulation, ease backache and generally help you feel well.

Stomach-strengthening exercises

As your baby gets bigger, you may find that the hollow in your lower back increases and this can give you backache. These exercises strengthen stomach (abdominal) muscles and ease backache.

• Start in a 'box' position (on all fours) with knees under hips, hands under shoulders, with fingers facing forward and abdominals lifted to keep your back straight.
• Pull in your stomach muscles and raise your back up towards the ceiling, curling the trunk and allowing your head to relax gently forward. Don't let your elbows lock.
• Hold for a few seconds then slowly return to the box position.
• Take care not to hollow your back; it should always return to a straight/neutral position. Do this slowly and rhythmically 10 times, making your muscles work hard and moving your back carefully.
• Only move your back as far as you can comfortably.

Pelvic tilt exercises

• Stand with your shoulders and bottom against a wall.
• Keep your knees soft.
• Pull your tummy button towards your spine, so that your back flattens against the wall; hold for 4 seconds and release.
• Repeat up to 10 times.

Pelvic floor exercises

Pelvic floor exercises help to strengthen the muscles of the pelvic floor, which come under great strain in pregnancy and childbirth. The pelvic floor consists of layers of muscles that stretch like a supportive hammock from the pubic bone (in front) to the end of the backbone.

Are there any exercises I should avoid?

While most exercise should be fine during your pregnancy, there are a few things you should avoid:

• lying flat on your back, particularly after 28 weeks, because the weight of your bump presses on the big blood vessels and can make you feel faint and reduce blood flow to your baby
• contact sports where there’s a risk of being hit, such as kickboxing, judo, squash, tennis, football and hockey
• horse riding, downhill skiing, ice hockey, gymnastics and cycling, because there’s a risk of falling
• significant changes in pressure, as in scuba-diving, because the baby has no protection against decompression sickness and gas embolism (gas bubbles in the bloodstream)
• exercise at more than 2,000m above sea level until you have acclimatised to avoid the risk of altitude sickness (a decrease in oxygen)
• repetitive high-impact exercise, or exercise with lots of twists and turns, high stepping or sudden stops that cause joint discomfort
• exercise where you get too hot since your body’s temperature is slightly higher when you are pregnant and intensive exercise may cause your core temperature to rise to an unsafe level for your baby
• drink plenty of water, wear lightweight clothing and only exercise in cool, well-ventilated places (no spas or saunas)

Are there any reasons why I shouldn’t exercise?

If your pregnancy is complicated or you have existing serious health conditions, this could affect your ability to exercise. If you have any of the following conditions, speak to your doctor or obstetrician before you start:

• pre-eclampsia
• placenta previa
• multiple pregnancy
• high blood pressure
• bleeding during the second or third trimester
• weak cervix, sometimes called cervical insufficiency or incompetent cervix, when the cervix opens too early and silently during pregnancy
• ruptured membranes or at risk of preterm labour
• poorly-controlled type 1 diabetes, hypertension or thyroid disease
• serious cardiovascular, respiratory or systemic disorders

When should I stop exercising?

Signs that you need to stop exercising and should see your doctor or midwife immediately include:

• chest pain
• unexplained shortness of breath
• dizziness, feeling faint or headache
• muscle weakness
• calf pain, swelling or redness
• sudden swelling of the ankles, hands or face
• vaginal bleeding
• nausea and vomiting
• reduced movement of your baby

Consult your doctor, physiotherapist or healthcare professional to make sure your exercise routine is not harmful for you or your baby.

Where can I get more information about exercising during pregnancy?

You can read more from the Department of Health Guidelines for physical activity during pregnancy.

For more information about exercising during pregnancy, speak to your doctor, midwife, obstetrician or physiotherapist.

Call Pregnancy, Birth and Baby on 1800 882 436 to speak to a maternal child health nurse.