Should women exercise during and after pregnancy?

Michelle Bridges was this week branded “irresponsible” and accused of providing a “poor message” to new mums following an Instagram post of her workout one month after giving birth.

The workout boasts 56 minutes of exercise – 32 minutes of jogging and 24 minutes of walking in intervals. Prefaced with the self-recognition of an experienced trainer, it was therefore advised that women “dial down” the duration to “15-20 minutes of total work”.

The offending Instagram post Screenshot, CC BY

Young women of reproductive age are a high-risk group for sedentary behaviour. They also face increased barriers to physical activity including family and work commitments. So it’s commendable to advocate for women to be physically active after giving birth.

However, exercise prescription in a public forum is not individualised or tailored to medical, physiological and musculoskeletal variations that exist during pregnancy and after giving birth.

While it’s important women are encouraged to be physically active during this time, it’s important to consider the type, frequency, intensity and duration of physical activity. This should always be done in conjunction with a health-care professional based on your individual fitness, health and your pregnancy.

Fairfax media reported new mums are generally advised against running for three months after birth. However, this doesn’t seem to be backed up by evidence, at least for a normal uncomplicated pregnancy. This recommendation is more appropriate where surgical interventions have been needed or musculoskeletal injury occurred during pregnancy and/or child birth.

Exercise during pregnancy

In the absence of specific national recommendations for pregnancy and after giving birth, otherwise healthy women are advised to follow national physical activity recommendations for Australian adults. This includes accumulating 150-300 minutes of moderate physical activity each week.

Any activities or exercise undertaken at this time should be at a pace that is comfortable for you, not cause you to overbalance or place extreme forces or pressure on any of your joints.

Usual exercise routines will require higher-than-normal efforts to complete. As such, these should be altered to a lighter intensity based on how you feel. Be aware that your body will be changing shape and physiology as it adapts to your pregnancy.

For women used to running, we would recommend progressing to moderate to light jogging or brisk walking. Weight lifters could perhaps consider modifying their exercise programs to incorporate aerobic-style activities of light to moderate intensity with less weight-bearing exercise. Specialised yoga and pilates classes for pregnancy are also widely available.

The aim is to maintain or improve fitness to cope with pregnancy, not train for competition. The most important thing is that you are aware of warning signs that indicate you should stop exercising. These include vaginal bleeding, regular painful contractions, amniotic fluid leakage, breathlessness before exertion, dizziness, chest pain, muscle weakness affecting balance and calf pain or swelling.

Bridges' biggest mistake is giving advice that’s not individualised. AAP

These recommendations do not apply to pregnant women who have heart or lung disease, incompetent cervix (weak cervical tissue leading to premature birth), are pregnant with twins or triplets with risk of premature labour, persistent second- or third-trimester bleeding, placenta previa (where the placenta is in the wrong place) after 26 weeks gestation and pre-eclampsia, where exercise and physical activity should be avoided unless under strict medical supervision.

With a safe upper level of exercise intensity during pregnancy yet to be established, an activity that can be easily quantified to monitor the intensity and exertion is recommended, specifically sticking to moderate levels of exertion.

We recommend gauging exercise intensity using a rating of perceived exertion scales. Women might aim to reach exertion levels of 13-14 on a scale of 6 to 20, where 7 is very very light, 11 is fairly light, 13 is somewhat hard, 15 is hard and 19 very very hard. Examples of safe exercise activities to start or maintain during pregnancy include:

• walking

• swimming

• aqua-aerobics

• stationary cycling

• low-impact aerobics

• modified Yoga

• modified Pilates

• running and jogging (after consultation with health-care team)

• modified strength training.

There is little evidence to suggest regular moderate intensity exercise throughout pregnancy is detrimental to the baby’s development or birth weight, or that it increases the risk of preterm birth, or raises maternal body temperature sufficiently to impose risk.

In normal pregnancies, and when physical activity is at recommended levels, there is general agreement the benefits of exercise far outweigh any risks. Contact or high-risk sports should obviously be restricted.

Despite the recommendations and minimal risk, pregnancy is usually associated with decreased levels of activity. Concerns about safety and potential adverse effects on the developing baby, as well as changing body shape, tiredness and time constraints are the most common barriers for women during pregnancy.

Exercising during pregnancy, however, has many benefits. These include decreased likelihood of gaining weight, gestational diabetes, hypertensive disorders such as pre-eclampsia, and of needing medical interventions during birth, including caesarean sections.

Exercising after giving birth

Latest guidelines suggest physical activity can be resumed gradually after giving birth as soon as is medically safe, depending on the mode of delivery, and in the absence of other health issues.

Depending on each woman’s personal circumstances, even after an uncomplicated vaginal delivery, there will be a need for rest and recovery. This physically demanding experience is associated with significant hormonal changes required to return the uterus to its pre-pregnant state while switching on milk production to sustain the newborn baby.

Return to exercise should be gradual and in conjunction with a health-care professional. Within hours or days of the delivery, this may mean starting to walk in short bouts (three to five minutes) a few times a day, gradually building up to longer and harder sessions of 20-30 minutes.

Alongside a resumption in exercise, women should regularly practise pelvic floor exercises. Returning to pre-pregnancy exercise regimens or sporting activities should be a gradual process of reconditioning yourself in small increments over weeks and months depending on your personal circumstances.

In the absence of complications, resumption of moderate activity has not been associated with any adverse effects. No negative impact has been found on breast milk composition and volume, provided adequate food and fluid intake is maintained, or on infant development.

On the plus side, exercise has been shown to help prevent weight gain in the period after giving birth, and may promote modest weight loss (around 1.5 kg). It has also been found to reduce the severity of postnatal depression by 50-60% – irrespective of the exercise intensity (light/moderate/vigorous), and especially when undertaken in group environments.

Women wishing to start or maintain exercise routines during and after pregnancy are recommended to seek advice from their health-care team including an obstetrician, gynaecologist, midwife, general practitioner, or accredited exercise physiologist.