Exercise in Pregnancy

Questions about exercise are common at the first antenatal visit. For example, how much can I exercise? What types of exercise can I do? How intense can the exercise be and what exercises do I need to avoid? Can I exercise too much in pregnancy?

Some pregnant women may lead sedentary lifestyles and will not be used to taking any regular exercise. They may be overweight or obese, but because they are pregnant may be willing to make healthier lifestyle changes.

For most pregnant women, where there are no obstetric complications, physical activity is both safe and desirable. Benefits may include less nausea and heartburn, less stress and anxiety, better bowel habits, better sleep and less lower back pain.

In addition there is evidence that physical activity may prevent certain complications of pregnancy and improve pregnancy outcomes. For example, the chance of developing gestational diabetes can be reduced by over 50%, even in sedentary women, by engaging in a programme of brisk walking. There is some evidence that regular aerobic exercise in pregnancy may help prevent the development of blood pressure problems (pre-eclampsia). Looking at the longer term, there is evidence that exercising in pregnancy can reduce the risk of subsequent childhood obesity in babies.

Pregnant women who are not used to regular exercise should aim to spend a minimum of two to three hours each week on aerobic exercise. These sessions should be spread throughout the week. Women who are used to exercising before they became pregnant can exercise at somewhat greater intensity. As a general rule you should still be able to carry on a conversation while you are exercising without undue breathlessness. A general guide is given in the table below:

Pre-pregnancy fitness Kilocalories per week Days per week Target maximum heart rate Exertion rate Example
Poor to fair (sedentary lifestyle) 1000-1500 5+ Up to 144 Fairly light 30 minutes swimming, walking or stationary bicycle at mild to moderate pace
Fair to average (occasional exercise) 1500-2000 5+ Up to 150 Somewhat hard At least 30 minutes swimming, walking or stationary cycling at moderate to brisk pace, plus resistance training
Good to elite (regular exercise program) 2000+ 5+ Up to 155 Somewhat hard to hard At least 30 minutes of swimming, jogging or stationary cycling at moderate to vigorous pace, plus resistance training

In general most physical activities are safe if you are sensible and:

  • Stop if you are tired
  • Stop if you have any pain
  • Do not become overheated
  • Make sure you have suitable clothing and footwear
  • Maintain a good level of hydration

Some women already have a very high level of fitness when they become pregnant and may want to continue with their pre-pregnancy regimes. You need to understand that being pregnant will reduce your competitive ability in your chosen sport. If you are one of these women you need to be careful not to let your core body temperature rise about 39° Celsius – particularly early in pregnancy as there is a higher rate of miscarriage. Marathon running or exercising in very hot and humid environments should be avoided in pregnancy. Later on in pregnancy elite athletes need to ensure that they don’t get overuse injuries of their tendons, joints and bones, particularly in the second half of pregnancy when joints and ligaments soften up due to the effect of the hormone Relaxin. High impact sports should be avoided - as should excessive stretching.

Exercise in water (eg. aqua aerobics) is great for most pregnant women as the water helps to reduce harmful rises in your body’s core temperature and water buoyancy means there is minimal risk of joint injury. A number of local swimming pools offer aquafit classes and these are suitable for most pregnant women. However spa baths should be avoided and scuba diving is not allowed.

We can put you in touch with local exercise physiologists and trainers who have specific interests in pregnancy and post-natal fitness.