The beneficial role of physical activity and exercise in the prevention of chronic diseases such as type 2 diabetes has been proven by many large-scale studies. Some investigations have also suggested a role for exercise in the management of type 2 diabetes, highlighting for instance its benefits on glycemic control. One study has shown that high-intensity interval training could help patients with type 2 diabetes control their blood glucose levels. Whether this type of training is easily implementable in patients with type 2 diabetes (often characterized by important comorbidities) is, however, unknown. In our modern society where fewer opportunities exist for exercise and/or incidental (nonexercise) physical activity, simply interrupting sedentary behaviours has been suggested to improve the management of patients with type 2 diabetes. Whether (and how) interrupting prolonged sitting in patients with type 2 diabetes can have benefits remains to be demonstrated.
A study performed at the Baker IDI Heart and Diabetes Institute in Melbourne, Australia and published in Diabetes Care shed light on this issue. In this study, 24 inactive and overweight or obese patients with type 2 diabetes were enrolled in a randomized crossover trial that tested 3 conditions over an 8-hour period each: 1) uninterrupted sitting; 2) sitting plus 3-minute bouts of light-intensity walking (LW) every 30 minutes; and 3) sitting plus 3-minute bouts of simple (weight-free) resistance activities (SRA) every 30 minutes. Each condition was separated by periods ranging from 6 to 14 days and was preceded by the consumption of a standardized meal. Blood levels of glucose, insulin, C-peptide (a marker of endogenous insulin secretion) and triglycerides were monitored during each 8-hour period. Interestingly, both interventions (LW and SRA) led to significant changes in cardiometabolic risk parameters. For instance, LW and SRA reduced responses of glucose (-39% for both), insulin (-36% with LW and -37% with SRA) and C-peptide (-27% with LW and -30% with SRA). SRA, but not LW also significantly decreased triglyceride response (-40%).
Although this trial included a small number of patients and that the reported changes were studied only during one day, this is an interesting proof-of-concept trial which suggests that interrupting prolonged sitting could help manage cardiometabolic risk markers in patients with type 2 diabetes. Hopefully longer studies testing the hypothesis that interrupting prolonged sitting could eventually help patients with type 2 diabetes control their blood glucose levels and reduce their risk of microvascular and cardiovascular complications over a longer period will be conducted. In the meantime, this study does suggest that short and regular bouts of aerobic or resistance exercise are both well tolerated and well accepted strategies to improve glucose control in patients with type 2 diabetes. This study also suggests that virtually any amount of exercise of any type can be of help in this high-risk population. Stakeholders in the healthcare systems around the world need to consider these kinds of studies and implement strategies that will facilitate the access to resources that can help patients with type 2 diabetes interrupt sedentary time and move more.