1. GDM can affect both mother and baby

Gestational diabetes mellitus (GDM) is a metabolic condition of pregnancy leading to glucose intolerance. 

It has maternal risk factors that are unavoidable including ethnicity, increased age, GDM history in past pregnancies, history of polycystic ovarian syndrome and family history of hyperglycaemia (Savvaki et al 2018). 

While these factors cannot be modified, evidence shows that there are significant lifestyle factors that contribute to the presentation of GDM. 

They include poor nutrition and diet, a sedentary lifestyle, obesity and hypertension. 

These factors may be present before conception and if they are addressed, the risk of developing GDM can be reduced.

GDM affects both the pregnant person and the baby. 

For the mother or birthing parent, there is an increased risk of caesarean section or instrumental delivery, preterm birth, high blood pressure, pre-eclampsia and excessive weight gain, along with a decreased rate of breastfeeding and a higher chance of developing diabetes later in life. 

For the baby, there is an increased risk of higher birth weight, leading to a higher risk of future obesity and cardiovascular disease, and an increased risk of developing diabetes later in life. 

They are also more likely to develop jaundice and/or breathing difficulties after birth.

2. Exercise helps prevent or reduce the severity of GDM

Exercise is important throughout pregnancy, even in the early stages. 

In the first 20 weeks, participation in exercise reduces the risk of developing GDM by 50 per cent (Dempsey et al 2004). 

Although administration of the glucose tolerance test is recommended between 24 and 28 weeks, diet and exercise interventions
should be undertaken as early as possible (Nankervis et al 2018).

Those who do go on to develop GDM will have an increased risk of developing type 2 diabetes in the 10 years following
pregnancy (Vounzoulaki et al 2020). 

As such, it is important to consider maternal health beyond the duration of pregnancy.

There is consensus in the literature, however, that compliance with exercise is particularly challenging post-delivery.

People who have experienced GDM benefit from structured and supervised exercise programs, often provided by a physiotherapist (Menek & Kaya 2024).

Aerobic exercise has been shown to reduce blood glucose levels by promoting insulin secretion (Bgeginski et al 2017). 

In a small study, resistance training was shown to lower capillary glucose levels (de Barros et al 2010). 

Resistance training may also have a more prolonged effect by lowering fasting blood glucose levels the next day (Padayachee & Coombes 2015).

3. Exercise equates to energy in GDM management 

Exercise is an important part of a healthy lifestyle. This is no different in pregnancy; in fact, it is particularly crucial in managing
GDM. 

Pregnancy is often very taxing so people will avoid exercise to reduce the impact of this fatigue. 

Unmanaged blood sugar levels in GDM can then compound feelings of tiredness. However, fatigue and energy are both greatly improved by regular exercise (Wender et al 2022).

Physiotherapists should bear in mind that mental health significantly affects energy levels (Gordon et al 2017).

Exercise also affects the energy the human body produces on a cellular level because it causes mitochondrial
biogenesis, among other processes (Hargreaves & Spriet 2020). 

Mitochondria convert glucose from food and oxygen into a fuel source, particularly for the brain and muscles. 

More fuel for these important organs means more energy for the whole system to run smoothly.

4. More sleep and less stress improve blood sugar levels in GDM 

Pregnancy can affect sleep quality and is associated with an increased prevalence of mood disorders. 

Both poor sleep and mental stress can be detrimental for blood sugar regulation (Xu et al 2018).

GDM itself can negatively affect mental wellbeing; some women report frustration related to the diagnosis itself along with
fear and anxiety about the pregnancy and foetus. 

Diet is often tightly monitored, leading to a loss of agency and control (Benton et al 2023). 

Although an association between poor sleep and GDM has been observed, it is not yet known whether actively trying to improve sleep quality can regulate blood sugar levels (Twedt et al 2023). 

However, it has been observed that physical activity during pregnancy is associated with improved sleep quality (Borodulin et al 2010, McCarthy et al 2023).

Exercise during pregnancy can help support mental wellbeing and the management of mood disorders, which may be another mechanism through which exercise helps manage GDM (Davenport et al 2018). 

Notably, a wide range of physical activity is included in these studies; it does not appear that one style of exercise is significantly superior to another.

5. People with GDM should aim for enjoyable exercise three times a week

General guidelines for exercise in pregnancy recommend 150–300 minutes per week for all pregnant people (Tsakiridis
et al 2020). 

However, specific guidelines for GDM are lacking. Women and birthing parents with GDM want clear and simple messaging about how to safely navigate physical activity in pregnancy (Harrison et al 2019). 

Despite the strong evidence supporting exercise to manage GDM, compliance is low (Smyth et al 2023). 

Barriers to exercise include lack of understanding of what to do, limited available time, lack of social support, lack of interest and other pregnancy-related issues (eg, fatigue and pelvic girdle pain) (Harrison et al 2018).

So what exercise is best? 

A Cochrane Review looking at 11 randomised controlled trials concluded that exercise in general helped manage blood sugar levels in GDM (Brown et al 2017). 

Traditionally, many studies have focused on aerobic exercise. While both aerobic exercise and resistance training can reduce postprandial blood glucose levels (Harrison et al 2016), a recent randomised controlled trial found that resistance training had a larger impact (Xie et al 2022). 

Blood sugar management during pregnancy can be highly intricate and this study conducted all exercise sessions after a meal to minimise the risk of post-exercise hypoglycaemia.

Given the impact of mental health on blood sugar levels and vice versa, it may be more important to focus on undertaking exercise that a person finds enjoyable and safe. 

The aim should be to exercise at least three times per week at a moderate intensity (Harrison et al 2016). 

Exercise should be enjoyable and prescribed with pregnancy safety measures in mind. 

Combining supervised group exercise sessions with educational support may empower people with GDM.

This may help with the exercise compliance issues often noted in this population and enable much needed behaviour change.

Dr Anita Bir FACP is a Melbournebased Specialist Women’s, Men’s and Pelvic Health Physiotherapist (as awarded by the Australian College of Physiotherapists in 2022) working in specialist clinics in East Melbourne and Kew East. Anita is the vice chair of the APA Women’s, Men’s and Pelvic Health national group and chair of the Victorian group.

Phoebe Kipen APAM is a physiotherapist and clinical Pilates instructor working in private practice at Physiosports in Brighton, Melbourne. Phoebe is a member of the APA Women’s, Men’s and Pelvic Health Victorian group. She has a special interest in reproductive health in sporting populations.

Quick links:

• References
• Infographic