Exercise plays an important role in promoting health and wellbeing for pregnant women. Women who exercise during pregnancy experience reduced weight gain, more rapid weight loss after pregnancy, improved mood and improved sleep patterns. Some studies have also shown that women who exercise regularly during pregnancy tend to be in labour for shorter periods of time, have a lesser likelihood of requiring epidural analgesia and have fewer operative births (caesarean sections).
However, pregnancy is a highly complex physiological state, and precautions are needed to ensure that your exercise program does not contribute to complications. Consult your doctor before you get started on a pregnancy fitness program, as your fitness status may need to be evaluated. And remember, don’t become complacent because your first pregnancy was easy as no two pregnancies are ever the same, and your body may well adjust differently.
When is exercise dangerous during pregnancy?
There are certain conditions in which it is not safe for a pregnant woman to exercise at all:
- Heart disease
- Three or more previous miscarriages
- Vaginal bleeding
- Ruptured membranes
- Incompetent cervix
- Incompetent cervix
- Twin pregnancy
- Premature labour
If you have any of the following conditions, you should only exercise with your doctor’s permission, and preferably under the supervision of a professional trainer:
- High blood pressure (hypertension)
- Thyroid disorders
- Diabetes
- Anaemia or other blood disorders
- Palpitations or irregular heart rhythms
- Excessive weight gain/loss
- History of precipitous labour (very rapid onset of labour)
- History of intrauterine growth retardation
- History of bleeding during pregnancy
- Breech presentation late in pregnancy
What are the benefits of exercising during pregnancy?
If complications don’t limit your ability to exercise throughout your pregnancy, exercise is beneficial for both you and your baby. Exercise during pregnancy offers many physical and emotional benefits:
- It can make you feel healthier. Exercise will enhance your feeling of well being, improve energy levels and help prevent depression, which is a lot more common in pregnancy than most people realise. Certain exercises can strengthen and tone muscles in the back, buttocks and thighs, improving posture and relieving pelvic and rectal pressure as well as backache. Specific exercises can reduce constipation by accelerating movement in your intestines, while others can prevent wear and tear on your joints (which become loosened during pregnancy by normal hormonal changes) by activating the lubricating synovial fluid in your joints. Exercise also releases endorphins, naturally occurring chemicals in your brain that help raise your spirits. It helps you look better, too, by stimulating circulation. It also helps you sleep better
- It helps you prepare for birth as strong muscles and a fit heart can ease labour and delivery. Gaining control over your breathing can help you manage pain, and in the event of a lengthy labour, increased endurance is a considerable help
- It helps you get back in shape more quickly. Women who exercise before becoming pregnant and who continue to do so during pregnancy are likely to gain less fat during pregnancy. Exercising during and after pregnancy also makes it easier to lose weight once the baby is born.
Exercise, in moderation, is beneficial in pregnancy, but be sure to check with your doctor or gynaecologist before starting an exercise program when you are pregnant
Moderate exercise when you are pregnant is not only healthy for you but also for your baby, providing a host of physiological and psychological benefits during and after your pregnancy. Make sure that you consult your doctor or gynaecologist before you start an exercise program, to ensure that it is safe for you and you baby.
During pregnancy the body goes through many changes, some physically evident and others not so obvious. It is important to find out as much about your body as you can, so you can understand the changes and the effects they have on your body during your pregnancy.
Physical changes during pregnancy that alter exercise abilities:
- Musculoskeletal changes. As the womb gradually becomes larger, the lower back develops more curvature and your centre of gravity shifts. This can alter your sense of balance and requires adjustments in posture to prevent injury. You may find you need to adjust your exercise program to accommodate these changes as you get closer to full term. The joints also undergo changes during pregnancy. Your body needs to adjust its size to make room for the birth of the baby, so it releases a hormone called relaxin that loosens up the joints and ligaments which is particularly necessary around the pelvis area. All of the joints in the body are substantially looser than normal and there is a greater chance of spraining or straining muscles and joints during pregnancy
- Lungs and breathing. During pregnancy the body has to work harder to give enough oxygen to the developing foetus. This can reduce the amount of oxygen available for exercise and can cause decreased endurance and a sense of breathlessness
- Metabolism. When you are pregnant your body uses carbohydrates more quickly. Exercise also increases the metabolism of carbohydrates. These two factors can lead to low blood sugar levels during exercise. Increasing food intake to ensure stable blood sugar levels is very important for pregnant athletes
- Cardiovascular changes. Blood volume is increased by about 40% during pregnancy, while heart rate increases by about 15 beats per minute, ensuring efficient transport of nutrients and oxygen to the foetus. However, as the womb grows, it requires a lot of blood flow, and light-headedness can occur.
Moderation is best!
While it is no longer disputed that exercise during pregnancy is healthy, strenuous exercise can be detrimental to your physical condition and that of your developing baby. Below are a few of the negative effects that excessive exercise can have during your pregnancy:
- Cardiovascular effects. During exercise, the muscles require more oxygen. Blood flow is diverted from your internal organs so that your muscles, lungs and heart get a larger share of oxygen. Intense physical activity during pregnancy can cause too large of a shift of oxygen away from the uterus and should be moderated, and the duration of each exercise session gradually reduced
- Neurotransmitter release. During exercise the brain releases more norepinephrine, a neurotransmitter that can reduce depression and influence blood flow to the heart and kidneys. Norepinephrine also increases smooth muscle contraction and can cause increased uterine activity in the form of painless contractions. These contractions have not been shown to cause labour, but because of the possible influence on contractions, women who have risks for preterm labour should be cautious
- Elevated Body Temperature. Exercise causes an increase in core body temperature. Avoid exercising in extremely hot weather as it is not healthy for your baby to become overheated. Temperatures exceeding 39 degrees C could cause problems with the developing foetus, particularly in the first trimester as this may lead to birth defects
The key to safe exercise during pregnancy is to listen to your body. There is a range of factors that are likely to affect your exercise ability during pregnancy and it is important to be aware of how your body adjusts itself to your pregnant condition. Look out for the vital signs that you should slow down or even curtail your program
- Anaemia. Also known as a low blood count, anaemia occurs when the oxygen-carrying capacity of the blood decreases. This has a big impact on endurance and may result in a marked decrease in your exercise capability, signalled by breathlessness, dizziness and fatigue. An iron-rich diet, iron supplements and extra vitamin C are ways of avoiding anaemia. Consult your doctor if you have any of these symptoms
- Contractions. Some women experience contractions throughout their pregnancy. While pre-term contractions do not always lead to pre-term birth, they do significantly increase the risk of pre-term labour. If you have frequent contractions during your pregnancy, strenuous exercise may lead to a higher rate of contractions. Exercise programs should be adjusted to include more non-weight bearing exercise like yoga, stretching and swimming rather than speed walking or jogging
- Lower back pain. Many women experience lower back pain or leg pain (also known as sciatica) during pregnancy as a result of weight gain and changes in body posture. Weight-bearing exercise can increase pain levels and further stress the joints. Non-weight bearing exercise, particularly swimming, often helps to relieve these symptoms
Avoid exercise during pregnancy if you have the following conditions:
- Placenta Praevia/vaginal bleeding. Placenta praevia is a condition where the placenta grows low in the uterus and actually covers the opening to the cervix. It can cause severe bleeding during pregnancy. Women with placenta previa or with vaginal bleeding of an unknown cause should not participate in an exercise program
- Pre-term labour or history of pre-term labour. Women who have previously delivered a baby before 36 weeks of pregnancy should be very cautious when participating in an exercise program during the second and third trimesters of any subsequent pregnancy. Weight-bearing exercises should be avoided, and replaced with stretching, yoga and walking. Also, women with pre-term contractions should avoid exercise that increases uterine contractions, whether painful or painless
- Intrauterine growth retardation (IUGR). This refers to poor growth of the baby. If your baby has IUGR, it may mean that the baby is not getting an adequate oxygen supply from the placenta. There are many causes of IUGR including smoking, drug use, infections and poor blood flow to the placenta. Because exercise shifts blood flow away from the placenta, moms with an IUGR pregnancy should not partake in an exercise program
- High blood pressure (toxaemia). Anyone with high blood pressure can benefit from a regular exercise program. However, women who develop high blood pressure during pregnancy should curtail their exercise program. Toxaemia, also known as Gestational Proteinuria and Hypertension, or high blood pressure that develops during pregnancy, is thought to involve a severe problem with blood vessels throughout the body. Exercise can worsen toxaemia and should be avoided
- Twin pregnancy. Women who are pregnant with more than one foetus have a higher risk of complications. Exercise should be limited to non-weight bearing and should focus on toning and stretching
- Heart disease. Exercise increases the strain on the heart and pregnancy also has this effect, because of the increased blood volume the heart has to work with. Women with heart problems should exercise only under the supervision of their cardiologist and gynaecologist.
Remember, pregnancy is a complicated physical condition. Be fair on your body – do exercise it (if all is well) but don’t overdo it.