INTRODUCTION
Gestational diabetes mellitus (GDM) is the most common pregnancy complication which impacts at least 14% of pregnancies globally [1–3]. GDM is a form of diabetes that occurs in pregnancy and although usually subsides following delivery it can have lasting implications for mother and child [4, 5]. GDM is associated with an increased risk of pregnancy complications such as macrosomia, caesarean sections, and a higher risk of developing type 2 diabetes and cardiovascular disease in the future compared to women with pregnancies without GDM [6–8]. Given the increased risk for complications such as macrosomia with increasing postprandial glucose concentrations [9], therapies that aim to specifically address postprandial hyperglycaemic excursions could play a vital role in the frontline treatment of GDM.
Postmeal walking, or walking after three main meals, has been proposed as a potential strategy to target postprandial hyperglycaemia in populations with diabetes [10–15]. Postmeal walking has been shown to reduce hyperglycaemia in people with type 2 diabetes and women at risk of GDM [12, 13, 16, 17], however the available research on women with GDM have presented varied responses [10, 11, 18]. Here, one bout of postprandial walking [18] or three bouts of postmeal walking [10] lowers postprandial glucose compared to sitting. Whereas, compared to usual care (i.e., not sitting, in a free-living non laboratory environments) three 10-min postmeal bouts were similar to 30-min of continuous walking for glycaemic control [11]. Given the need for more therapeutic options that are translatable and effective for the management of GDM a longer-term intervention from diagnosis to delivery, in a free-living environment, that compares postmeal walking against the current standard care from diagnosis through to delivery is warranted.
During pregnancy, women are recommended to perform at least 150 minutes of moderate physical activity per week [19], however, only one in six women meet these recommendations [20]. Barriers to physical activity include lack of motivation, tiredness, pregnancy-related symptoms, and a lack of education regarding the guidelines [21]. Breaking up activity into shorter bouts is one strategy to reduce barriers of fatigue and lack of time. In addition, accumulating activity in three short bouts has shown similar health benefits for fitness, blood pressure, lipids, insulin and glucose, to one continuous bout in a systematic review and meta-analysis of 19 studies involving over 1000 community dwelling adults [22]. Therefore, a strategy to encourage women to overcome barriers to physical activity is necessary to ensure women with GDM are able to reach their standard-care guidelines.
In a randomised controlled trial, we examined the effect of a 7-week intervention of three daily 10-minute bouts of postprandial walking compared to standard-care guidelines on postprandial hyperglycaemia, fasting blood glucose, mean 24-h blood glucose, physical activity, and sedentary time. It was hypothesised that 10 minutes of postprandial walking three times daily would improve postprandial hyperglycaemia, fasting blood glucose, mean 24-h blood glucose, physical activity, and sedentary time in women with GDM compared to control standard guidelines which include recommendations to perform 30 minutes of continuous physical activity on most days.