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Canadian Journal of Cardiology

THE COMPARATIVE EFFECTS OF BURST EXERCISE VERSUS SUSTAINED EXERCISE ON THE CARDIOMETABOLIC STATUS OF NEWLY DIAGNOSED DIABETIC PATIENTS

      Background

      Physical activity is an integral part of diabetes rehabilitation. Historically, diabetes rehabilitation has employed low intensity, sustained exercise. Recent studies have demonstrated short-term cardiometabolic benefits of high intensity burst exercise in healthy volunteers. The impacts of burst exercise in diabetics have yet to be adequately assessed. This study compared the impacts of burst and sustained exercises on cardiometabolic factors including: BMI, exercise adherence, cardiopulmonary fitness (measured by stress test using the Bruce Protocol), blood sugar levels and lipid profiles in newly diagnosed diabetics.

      Methods

      76 newly-diagnosed diabetic patients were recruited from a local diabetes rehabilitation center. This sample size was determined based on power analysis of a previous 16 person pilot study. Patients were randomized into a control group prescribed routine sustained exercise (30 minutes at 60% age predicted target heart rate) and an intervention group prescribed a high intensity burst exercise regimen (3 periods of 10 minutes at 85% of target heart rate). All patients underwent routine blood tests, stress tests and logged exercise duration in logbooks. Patients were excluded from the study if they had comorbidities, conditions or took medications which would impact or alter the cardiometabolic parametres assessed in this study or their ability to perform burst exercise.

      Results

      76 patients were randomized with an average age of 65 years, an average BMI of 31 kg/m2 and an average Haemoglobin A1C (HBA1C) of 8.2%; 68% of study participants were male. Patients prescribed the burst regimen exercised on average 27% more than the control group (p<0.01). Burst exercise patients also showed a 2.3 fold greater improvement in HbA1c (0.25% improvement in the control group versus 0.81% improvement in the intervention group, p<0.01). In addition, there was significantly greater improvement in lipid parametres: LDL improving 0.16 mmol/L in the control group compared to 0.37 mmol/L in the burst exercise group and HDL improving 0.021 mmol/L compared to 0.14 mmol/L in the burst exercise group. The intervention group also improved more in their triglycerides, BMI and cardiopulmonary fitness. Even among patients who exercised similar number of minutes per day, greater relative improvements in biochemical parameters were noted in those randomized to burst exercise.

      Conclusion

      Burst exercise appeared to significantly improve the cardiometabolic status of newly diagnosed diabetic patients. This regimen may represent a simple and effective way to improve diabetes rehabilitation but requires longer-term validation of clinical outcomes in larger and more diverse populations.