It’s been conclusively proven that moderate exercise during pregnancy is good for the developing foetus, and a recent study showed that mothers who work out while they’re pregnant may even have smarter babies.
The study, carried out at the University of Montreal, assigned 10 pregnant women to an exercise group and eight to an inactive group at the start of their second trimester. The active group engaged in at least 20 minutes of moderate intensity cardiovascular exercise three times a week.
When the babies were eight to 12 days old, their brain activity was measured and the babies whose mothers had done some exercise showed a slight advantage.
Another recent study showed the health benefits of exercise in pregnancy could carry through into the babies’ adult lives. Researchers from California State University San Marcos in the USA and Universitätsmedizin Greifswald in Germany demonstrated that exercise can program a baby’s arteries to resist heart problems, and that those positive effects and benefits could continue into their adulthood.
But keeping fit in pregnancy isn’t only good for the developing baby. “Exercise in pregnancy has many benefits, not only for the mom but for the whole growing family,” says Dr Etti Barsky, training director at Preggi Bellies.
“It decreases the risks of pregnancy related aches and pains, improves recovery post delivery and helps control weight gain,” she explains. “It also results in a calm, healthy baby who’s able to cope with the physiological demands of labour. And exercise is a great stress reliever, and can help moderate those hormonal mood swings of pregnancy.”
How much is just enough?
Obviously, you need to be sensible about what exercise you do when you’re pregnant. Moderate intensity exercise is physical activity that, if you had to give yourself a score out of 20 for effort, you would get anything between 12 and 14.
“There’s also the talk test, where you should be able to string together two or three words comfortably,” adds Etti. “If you can’t even get one word out while exercising, you need to slow down; if you can have a long chat, you’re not working hard enough.”
Swimming, stationary cycling and brisk walking all achieve the 12 to 14 score, and are all safe for pregnant women. “Running, specialised prenatal aerobics and water aerobics, where the danger of abdominal trauma is minimal, are also fine,” says Etti.
“You should avoid contact sports, exercise at altitude, diving, and any exercise that involves jumping, jarring motions or rapid changes in direction.”
The typical clinical guidelines for pregnant women is moderate intensity exercise for 20 to 45 minutes, five days a week. This should be a mixture of aerobic activity and muscle strengthening activity. But remember if you can’t manage this, doing something is better than nothing.
Etti recommends supervised training with an instructor who’s specialised in looking after pregnant women. “In this way, you’re monitored so that everything you do is controlled and safe.
Your trainer must know all the contraindications to exercise in pregnancy, how to adjust your training for various conditions, and when to stop you from exercising when appropriate.”
Etti says that there aren’t specific exercises you should and shouldn’t do in each trimester. “The most important thing is to listen to your body,” she says. “As long as it’s comfortable, it should be fine.”
How exercise in pregnancy helps in labour
Studies have shown that fit mothers have easier, shorter and less complicated labour, including:
- 35% decrease in need for pain relief.
- 37% decrease in maternal exhaustion.
- 50% decrease in the need to artificially rupture the membranes.
- 50% decrease in the need to induce or stimulate labour.
- 50% decrease in the need to intervene due to abnormalities in foetal heart rate.
- 55% decrease in the need for episiotomy.
- 75% decrease in the need for operative intervention.
Types of exercise
- Aerobic exercise makes your heart and lungs work harder, and includes some normal activities that are part of your daily routine, such as fairly heavy housework, climbing stairs or gardening.
- Muscle strengthening exercise can include walking uphill, lifting or carrying shopping, weight training and yoga.
- Pelvic floor exercises are important to strengthen the muscles that take strain while you're pregnant and especially during labour.
Be safe and sensible
- Eat a small snack before you exercise and drink plenty of water to prevent overheating.
- Keep exercise sessions to no longer than 45 minutes.
- Regular exercise is preferable to occasional bursts of exercise.
- Avoid exercising in very hot or humid weather.
- Warm up first for about five minutes – slow walking or stationary cycling at low resistance are ideal.
- Cool down afterwards with some gentle stationary stretching (stretches should not be taken to the maximum resistance).
How much is too much?
“Exercise in pregnancy is all about balance,” says Etti. “It’s knowing how to balance the effects of exercise with the physiological changes of pregnancy, keeping your muscles conditioned so they can cope with the demands of the body but not straining them. And it’s about knowing when to modify training and when to stop.”
How will you know if you’ve overdone it? If you have any of the following symptoms during or after your regular workout, see a doctor to be on the safe side.
Dizziness, headaches and heart flutters
These could mean you’re exercising too hard, are dehydrated or don’t have enough iron in your blood.
Pain in your back or hips
Hormonal changes do make the ligaments a little looser and can make you more prone to injury.
Nausea or vomiting
These can be signs that your blood sugar is low or you have low blood pressure.
Sudden change in body temperature
If you get hot or cold flushes, this could mean that your body is struggling to regulate its internal thermometer.
Your feet and hands may puff up a little after exercise, but sudden, severe swelling in the second half of pregnancy can be a sign of pre-eclampsia.
There are a few symptoms that could mean something more serious. If you experience any of the following, see your doctor immediately:
- Fluid leaking from your vagina – although stress incontinence (leaking a little
urine) while exercising in pregnancy is common, it could be amniotic fluid.
- Calf pain – a sudden sharp pain, swelling or redness could mean a deep vein thrombosis.
- Blurred vision.
- Pain in your abdomen.
- Vaginal bleeding.
- Abdominal cramps or contractions.