Med Sci Sports Exerc. 2016 Oct 21;
PURPOSE: Prediabetes is linked to several modifiable risk factors, in particular, physical activity participation. The optimal prescription for physical activity remains uncertain. This pilot study aimed to investigate the effectiveness of continuous moderate intensity (CON) versus high intensity interval (HIIT) aerobic training in persons with prediabetes. Outcome measures included hemoglobin A1c (A1C), body composition, musculoskeletal and aerobic fitness.
METHODS: Participants (n= 35) were recruited and screened using a questionnaire plus capillary blood point-of-care A1C analysis. After baseline screening/exclusions, 21 participants were randomly assigned to either HIIT or CON training 3X per week for twelve weeks. All participants also undertook resistance training 2X per week. A1C, an oral glucose tolerance test, select measures of physical and physiological fitness were assessed at baseline and follow-up.
RESULTS: There were no significant differences in improvements in select metabolic indicators to training between CON and HIT groups. Pooled participant data showed a mean reduction in A1C of 0.5% (95%CI 0.3-0.7%), while β-cell function (%β) improved by 28.9% (95%CI 16.5-39.2%) and insulin sensitivity (%S) decreased by 34.8 (95%CI 57.8-11.8), as assessed by HOMA. Significant reductions in waist circumference of 4.5cm (p<0.001) and a 20% (p<0.001) improvement in aerobic fitness were also observed in both training groups.
CONCLUSION: The completion of a 12 week exercise program involving both resistance training and either HIIT or CON training, results in improved glycemic control, visceral adiposity and aerobic fitness in persons with prediabetes.