Introduction
Regular exercise can reduce the discomforts of pregnancy, such as excessive weight gain and fluid retention, and reduce the risks of certain complications occurring. Pregnant women must be careful about their exercise routine so they do not harm themselves or the developing foetus. During pregnancy, the body goes through many physiological changes, so the exercise routine should be modified accordingly.

About
Benefits
There are a number of benefits to be gained from exercising while pregnant. These may include improved weight control and fitness maintenance, reduced risk of developing gestational diabetes, increased strength and flexibility and enhancement of baby's birth weight.
When you should NOT exercise
It is recommended that pregnant women without medical or pregnancy-related complications have 30 minutes or more of moderate exercise a day on most, if not all, days of the week. Exercise during pregnancy is not recommended in women with the following medical or pregnancy-related complications: congestive heart failure, valvular heart disease, severe hypertensive disease, uterine bleeding, premature rupture of membranes or incompetent cervix. Women with anaemia, thyroid disease, medication-controlled diabetes, breech presentation in the third trimester, multiple pregnancy, essential hypertension or excessive weight gain or loss may be advised by their Doctor to avoid exercise during pregnancy.

Body changes during pregnancy
Heart - increased cardiac output, resting heart rate and blood volume.
Breathing - Diaphragm may be elevated, resting oxygen use increased.
Digestive system - constipation, increased gastric reflux and heartburn.
Musculoskeletal - changes to the centre of gravity, ligament and joint looseness, increase in breast size which can lead to upper back and shoulder pain.
Coordination - Balance skills are affected by changes in the centre of gravity. Modifying and/or avoiding activities that require significant balance skills (e.g. gymnastics) may be recommended during pregnancy.

Exercising safely during pregnancy
1. Drink plenty of water during and after exercise to prevent overheating and dehydration. Becoming overheated and dehydrated may increase the risk of having a preterm labour.
2. Wear ventilated clothing to avoid overheating.
3. Do not exercise while you have a fever.
4. Avoid exercising on your back, especially in the third trimester.
5. Avoid bouncing and jerky movements when exercising, especially in the third trimester.
6. Recommended low-impact activities include stationary bicycling, swimming, walking and low-impact aerobics.
7. Avoid activities such as scuba diving and mountain climbing, that involve potential low-oxygen states.
8. Minimise the risk of foetal ketosis by consuming complex carbohydrates to replace muscle glycogen lost during exercise.
9. Some sporting activities carry potential risks of foetal loss from pelvic or abdominal trauma. This is most relevant to women who are more than 20 weeks pregnant, as the uterus is relatively protected by the bony structures of the pelvis until around 12-15 weeks.
10. Avoid exercises that require significant use of Valsalva's manouever (e.g. weight lifting), especially in the third trimester.

Trained athletes
Trained athletes who are pregnant will need to modify the type and intensity of exercise they engage in.

Health care
Always consult your Doctor for diagnosis and advice. In no way is this information intended to replace the advice of a medical practitioner.
It is important to see your Doctor to discuss exercise/sports activities that are suitable for you during pregnancy.
Your Doctor may refer you to a Physiotherapist who is specially trained to advise and instruct you in the most appropriate exercise during your pregnancy.
There are antenatal classes that incorporate gentle exercise and relaxation techniques. Ask your Doctor for advice.