Glycaemic control is improved by 7 days of aerobic exercise training in patients with type 2 diabetes

Aims/hypothesis Cardiovascular events and death are better predicted by postprandial glucose (PPG) than by fasting blood glucose or HbA1c. While chronic exercise reduces HbA _1c in patients with type 2 diabetes, short-term exercise improves measures of insulin sensitivity but does not consistently alter responses to the OGTT. The purpose of this study was to determine whether short-term exercise training improves PPG and glycaemic control in free-living patients with type 2 diabetes, independently of the changes in fitness, adiposity and energy balance often associated with chronic exercise training. Methods Using continuous glucose monitors, PPG was quantified in previously sedentary patients with type 2 diabetes not using exogenous insulin (n013, age 53±2 years, HbA _1c 6.6± 0.2% (49.1±1.9mmol/mol)) during 3 days of habitual activity and during the final 3 days of a 7 day aerobic exercise training programme (7D-EX) which does not elicit measurable changes in cardiorespiratory fitness or body composition. Diet was standardised across monitoring periods, with modifications during 7D-EX to offset increases in energy expenditure. OGTTs were performed on the morning following each monitoring period. Results 7D-EX attenuated PPG (p<0.05) as well as the frequency, magnitude and duration of glycaemic excursions (p<0.05). Conversely, average 24 h blood glucose did not change, nor did glucose, insulin or C-peptide responses to the OGTT. Conclusions/interpretation 7D-EX attenuated glycaemic variability and PPG in free-living patients with type 2 diabetes but did not significantly alter responses to the laboratory-based OGTT. These effects appeared to be independent of changes in fitness, body composition or energy balance.