Question: Is progressive resistance exercise a safe and effective form of exercise to improve glycaemic control in people with type 2 diabetes?
Design: Systematic review with meta-analysis of randomised controlled trials.
Participants: People with type 2 diabetes mellitus.
Intervention: Progressive resistance exercise.
Outcome measures: The primary outcome was glycaemic control measured as percentage glycosylated haemoglobin (HbA1c). Secondary outcomes were body composition (lean body and fat free mass in kg), and muscle strength (% change in 1RM, dynamometry, change in maximum weight lifted).
Results: The search yielded nine relevant trials that evaluated 372 people with type 2 diabetes. Compared to not exercising, progressive resistance exercise led to small and statistically significant absolute reductions in HbA1c of 0.3% (SMD -0.25, 95% CI -0.47 to -0.03). When compared to aerobic exercise there were no significant differences in HbA1c. Progressive resistance exercise resulted in large improvements in strength when compared to aerobic (SMD 1.44, 95% CI 0.83 to 2.05) or no exercise (SMD 0.95, 95% CI 0.58 to 1.31). There were no significant changes in body composition.
Conclusions: Progressive resistance exercise increases strength and leads to small reductions in glycosylated haemoglobin that are likely to be clinically significant for people with type 2 diabetes. Progressive resistance exercise is a feasible option in the management of glycaemia for this population.