Can you exercise safely while pregnant?

There’s a lot of misinformation about the risks of exercising during pregnancy, but, as Lauren Drinkwater explains, done right it can have myriad benefits for mother and baby. Here's what to focus on in each trimester…

Published: November 16, 2023 at 11:14 am

To share a personal anecdote from the perspective of a no-longer-pregnant person, I recently clicked on an online workout to find myself feeling somewhat apprehensive at the sight of a pregnant instructor teaching a full-body strength session.

My initial thoughts were ‘would she be able to lift heavy weights and carry out all the moves herself effectively’ and ‘would I get a good enough workout from her’?

Given everything I know from personal experience, I had to deride myself for this preconceived notion.

Of course she would, and of course I would. The fact is a pregnant person is more than able to effectively teach a class, just as much as she is able to take on exercise herself.

I exercised during both of my pregnancies and taught back-to-back fitness classes when I was pregnant with my second child so, yes, it did bother me that my initial thought was to see her as somehow ‘less able’.

Overcoming stigma

Why is our first instinct to see a pregnant woman as weaker when in fact we’re looking at a super being with increased heart rate, lung capacity, stroke volume and cardiac output, as well as heightened senses, greater hair and nail growth, and more blood pumping through her veins?

Despite all the evidence to the contrary, exercise in pregnancy is somehow deemed unsafe and women have been told to stop exercising altogether for fear of hurting their fetus.

Several pregnant women have come to me worried because their instructors or PTs have told them they no longer feel comfortable with them doing the class or session.

Understandably they want to feel safe and they want their unborn babies to be safe. And though they are more than right to seek someone specialised in this field, their fear is not substantiated.

Exercising in pregnancy is not only beneficial for the mother-to-be, it also has a positive effect on the baby growing inside.

The benefits of exercising while pregnant

Let’s list some of those important benefits when it comes to exercising while pregnant:

  • Improved blood circulation between mother and baby via the placenta.
  • Less backache, improved posture and reduction in common pregnancy symptoms.
  • Faster postnatal recovery.
  • Control of excess weight gain.
  • Enhanced maternal wellbeing.
  • Improved sleep patterns.
  • Positive effect on ability to cope with labour and childbirth.
  • Decreased stress, anxiety and fatigue.
  • Helping baby into optimal position for birth.

Do you need to make some modifications or regressions to your workout during pregnancy?

In short, there’s no reason why you should stop doing the exercise you were doing before becoming pregnant. That said, there are things to take into account and be mindful of when exercising during these nine months.

Here's what to expect physically during the three trimesters and how best to exercise in each of those three trimesters.

First trimester

Tiredness An increase in levels of the progesterone hormone in your system can lead to increased fatigue and more need for rest.

Nausea The rising levels of hormones HCG (human chorionic gonadotropin), progesterone and oestrogen in your system can cause sickness, which can be triggered at any time of the day. A small percentage of pregnant women suffer from ‘hyperemesis gravidarum’, excessive vomiting during pregnancy. This can understandably impede any desire for exercise until it has subsided.

Relaxin This hormone relaxes the ligaments, muscles and joints to accommodate the growing baby and is produced around the second week of pregnancy, peaking by the end of the first trimester. The effect it has on fibrous tissue in the body takes approximately 3-5 months after birth to return to normal. Due to the effect of this hormone, it’s best to incorporate smaller stances when the legs are placed wide apart, and avoid developmental stretches when lengthening muscles in Pilates, yoga or in cool-down.

Sore breasts They may become tender, swollen and more sensitive due to increased blood flow and hormonal changes. It’s advised to take on less impactful exercise.

General advice

Many women can continue with their pre-pregnancy exercise during the first trimester if they feel comfortable.

Activities such as walking, swimming, stationary cycling, prenatal yoga and light jogging can help you maintain fitness. If you do experience morning sickness, fatigue or any other discomforts, listen to your body and make adjustments to the level of activity.

Second trimester

Energy After 18 weeks, the body requires an additional 300 calories per day to meet the demands of pregnancy. If undertaking exercise, ensure you are consuming enough calories to compensate.

Blood sugar levels Eat regularly. Pregnant ladies are more prone to hypoglycaemia or gestational diabetes as they burn increased levels of carbs and are more resistant to insulin. Snack 2-3 hours before and after exercise.

Body temperature Maternal temperature is slightly raised by 0.5 degrees during pregnancy so it’s important to not undertake exercise that will further increase your temperature. Make sure you drink water, little and often.

Fitness level If you have given up exercise in the first trimester but return during the second, build up fitness gradually and gently.

Abdominal muscles During pregnancy the ab muscles stretch widthways and lengthways to make room for the baby. Avoid any twisting and crunches once they have begun to stretch. These muscles help control the tilt of the pelvis and stabilise the spine, so it’s vital to exercise them to regain strength and tone after birth. Good exercises include static abdominal contractions, pelvic tilts engaging the muscles on all fours, adapted half plank, and bird dog pose.

General advice

The second trimester is usually considered the best time for exercise as the initial effects of hormones have lifted. However, some exercises may need to be modified.

Try low-impact activities that help with strength, flexibility and balance such as prenatal pilates, gentle weight lifting and modified yoga poses. Avoid exercises that involve lying flat on your back for long periods as this can stop blood flow to the uterus.

Third trimester

Considerations from the second trimester still apply, but the growing bump and added fatigue are additional factors.

Posture The baby can throw your body weight forwards and tilt your pelvis forwards, making balance difficult. Keep neutral spine alignment by lifting your chin and chest.

Exercise type In your second and third trimesters, avoid any exercises that involve jumping (to protect your pelvic floor), lying on your back or standing for too long (to avoid supine or postural hypotensive syndrome).

Pelvic floor As the baby grows, the increased weight places pressure on the pelvic floor. This, combined with hormonal changes, can weaken the pelvic floor muscles and lead to issues such as incontinence and pelvic organ prolapse. It’s a good idea to incorporate regular pelvic squeezes (kegel exercises) into your routine to maintain pelvic strength.

General advice

In the third trimester, the centre of gravity shifts as your bump grows, so you may feel less steady on your feet. Continue exercises that support the changes in your body.

Walking is a good option, as well as swimming and aqua aerobics which reduce stress on the joints. Prenatal yoga and stretching can help with flexibility and relaxation. Try to avoid activities that risk injury or falling such as high impact aerobics or contact sports.

Top image credit: Getty Images