Exercise during pregnancy – how much is ok?

Some exercise during pregnancy can be beneficial; but how much exercise is ok? And what type of exercise should you be doing during pregnancy?

The benefits of exercise during pregnancy

There are many proposed benefits of exercising during pregnancy. These include helping you cope with:-

• Labour
• Your changing shape and weight gain (1)
• Constipation
• Fatigue
• Varicose veins
• Circulation problems (2)

Researchers have found that exercising during pregnancy is linked to experiencing fewer discomforts later in pregnancy. (3)

It has also been suggested, by the American College of Obstetricians and Gynecologists (ACOG), that exercise could play a role in preventing and managing gestational diabetes. (4)

Gestational diabetes is a condition that frequently shows no symptoms. It does, however, pose a potential risk to both mother and baby.

Risks include the size of the baby being too small or large; heightened risk of pre-eclampsia; increased risk of premature birth; and heightened risk of respiratory distress syndrome in the baby when born. (5)

Research suggests that exercise aids those with gestational diabetes, as the movement of multiple muscles simultaneously increases insulin sensitivity. This results in enhanced glucose utilization. (6)

The limits to exercising during pregnancy

The ACOG outlines several signs that indicate the limit for exercising during pregnancy has been reached. They recommend ceasing exercise if any of the following occur:-

• Vaginal bleeding
• Shortness of breath prior to exertion
• Dizziness
• Headache
• Chest pain
• Muscle weakness
• Calf pain or swelling
• Preterm labor
• Decreased fetal movement
• Amniotic fluid leakage (7)

As a guide, the NHS recommends that during exercise when pregnant, you should still be able to hold a conversation, i.e. breathlessness is another indication that you are exercising too intensely.

Exercises to avoid during pregnancy

There are several types of exercise that should be avoided during pregnancy.

Contact sports, such as kickboxing, judo or squash, should be avoided as they pose the risk of being hit. (1)

Sports that present a risk of falling should also be avoided. These include:-

• Horseriding
• Downhill skiing
• Ice hockey
• Gymnastics
• Cycling
• Trampolining
• Rollerblading (1, 8)

Exercises that involve lying on your back, particularly after 16 weeks, should also be avoided. This is because the weight of the baby presses on the blood vessels, which can cause the flow of blood to the heart to be slowed. This may result in you feeling faint. (1, 8)

Scuba diving is another activity to avoid during pregnancy. An increased risk of decompression sickness is posed to the baby, due to the baby having no protection against it. (1, 7)

Exercises that should be done gently during pregnancy

In addition to avoiding certain exercises completely, exercises that put strain on joint and ligaments should be performed more gently.

This is particularly pertinent with high-impact aerobics, difficult yoga positions and jogging on the road.

The need for more gentle exercise comes as a result of the release of hormones during pregnancy which loosen joints and ligaments.

The hormones are released in order to prepare the body for birth – which involves the baby passing through the pelvis. (2)

Recommended exercises during pregnancy

Despite the recommended limits and exercises to avoid, there are still many types of exercise you can carry out during pregnancy. These include:

• Walking
• Swimming
• Cycling – on a stationary bike
• Water aerobics
• Yoga or pilates
• Special pregnancy exercise classes (8)

Pelvic floor exercises

Another type of exercise recommended during pregnancy is pelvic floor exercising. (9)

The pelvic floor consists of muscles that keep the bladder, vagina, uterus and bowel in place. They also help you to control bladder and bowel movements. (10)

During pregnancy, pressure is placed upon the pelvic floor, which is located in between the pubic bone and tailbone. (9, 10)

This pressure may result in weakening of the pelvic floor muscles. This may lead to stress incontinence, which is a condition where urine is leaked during activities such as coughing or sneezing. (1)

Performing pelvic floor exercises during pregnancy will also decrease your chances of having incontinence problems after childbirth. (11)

A good way to describe how to perform a pelvic floor exercise is to tense the muscles which you would use to halt the flow of urine. This should not, however, be performed during actual urination in pregnancy.

You should aim to hold the tension for around five seconds before relaxing. As a guide, try to perform five sets of ten a day. Your midwife will also be able to give you more information on these exercises and how frequently to perform them. (2)