A brisk evening walk before dinner does not affect glucose levels in people with Type 2 diabetes, according to University of Alberta research that contradicts previous findings.
“We found no difference between 50 minutes of walking in the afternoon and 50 minutes of sitting on the 24-hour glucose profile,” said Jordan Rees, a PhD student in U of A diabetes researcher Normand Boulé‘s Physical Activity and Diabetes Laboratory. “This was quite surprising given it was a bit different from studies we’ve seen in the past.”
The multi-site study followed 80 people with Type 2 diabetes for one week.
Participants fitted with a continuous glucose monitor were put on a standardized diet with eating instructions that included a lunch three to five hours before walking for 50 minutes, with dinner consumed immediately after.
Walking was chosen because it is a preferred mode of activity for people with diabetes and the afternoon was chosen for convenience for participants who work.
Rees said many previous short-term studies showing exercise has a beneficial effect on glucose levels in those with Type 2 diabetes were completed in the morning, typically after breakfast.
She explained when we eat a meal, our food gets absorbed into our bloodstream as glucose, which can cause a spike in our blood sugar.
“The thinking is if we can time our exercise to when we see that spike, we can use exercise, which uses glucose for fuel, to lower that spike we see after a meal,” she said. “However, the timing of walking in our study may not have been ideal to lower 24-hour glucose levels, as observed in previous studies.”
Despite moderate levels of exercise before dinner having no effect on blood sugar, Rees said her team still encourages exercise for the many health benefits it provides.
The Canadian Physical Activity Guidelines and the position statement of the American Diabetes Association recommend 150 minutes per week of moderate-intensity exercise.
“We just need to do more investigating around when is the most optimal time of day for this population to complete their exercise,” she said.
“We’re not sure what effect longer-term moderate exercise at different times of day will have on glycemic control—time of day and time of exercise around meals are important factors to consider.”