Effects of aerobic training, resistance training, or both on glycemic control in type 2 diabetes: a randomized trial.
BACKGROUND
Previous trials have evaluated the effects of aerobic training alone and of resistance training alone on glycemic control in type 2 diabetes, as assessed by hemoglobin A1c values. However, none could assess incremental effects of combined aerobic and resistance training compared with either type of exercise alone.


OBJECTIVE
To determine the effects of aerobic training alone, resistance training alone, and combined exercise training on hemoglobin A1c values in patients with type 2 diabetes.


METHODS
Randomized, controlled trial.


METHODS
8 community-based facilities.


METHODS
251 adults age 39 to 70 years with type 2 diabetes. A negative result on a stress test or clearance by a cardiologist, and adherence to exercise during a 4-week run-in period, were required before randomization.


METHODS
Aerobic training, resistance training, or both types of exercise (combined exercise training). A sedentary control group was included. Exercise training was performed 3 times weekly for 22 weeks (weeks 5 to 26 of the study).


METHODS
The primary outcome was the change in hemoglobin A1c value at 6 months. Secondary outcomes were changes in body composition, plasma lipid values, and blood pressure.


RESULTS
The absolute change in the hemoglobin A1c value in the combined exercise training group compared with the control group was -0.51 percentage point (95% CI, -0.87 to -0.14) in the aerobic training group and -0.38 percentage point (CI, -0.72 to -0.22) in the resistance training group. Combined exercise training resulted in an additional change in the hemoglobin A1c value of -0.46 percentage point (CI, -0.83 to -0.09) compared with aerobic training alone and -0.59 percentage point (CI, -0.95 to -0.23) compared with resistance training alone. Changes in blood pressure and lipid values did not statistically significantly differ among groups. Adverse events were more common in the exercise groups.


CONCLUSIONS
The generalizability of the results to patients who are less adherent to exercise programs is uncertain. The participants were not blinded, and the total duration of exercise was greater in the combined exercise training group than in the aerobic and resistance training groups.


CONCLUSIONS
Either aerobic or resistance training alone improves glycemic control in type 2 diabetes, but the improvements are greatest with combined aerobic and resistance training. ClinicalTrials.gov registration number: NCT00195884.
Sigal
Ronald J
RJ
University of Ottawa, Clinical Epidemiology Program, Ottawa Health Research Institute, and Prevention and Rehabilitation Centre, University of Ottawa Heart Institute, Ottawa, Ontario, Canada. rsigal@ucalgary.ca
Kenny
Glen P
GP
Boulé
Normand G
NG
Wells
George A
GA
Prud'homme
Denis
D
Fortier
Michelle
M
Reid
Robert D
RD
Tulloch
Heather
H
Coyle
Douglas
D
Phillips
Penny
P
Jennings
Alison
A
Jaffey
James
J
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure / Q000502:physiology; D001823:Body Composition / Q000502:physiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology / Q000628:therapy*; D005081:Exercise Therapy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010806:Physical Education and Training / Q000379:methods
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D008055:Lipids