The Acute Effects of Interval-Type Exercise on Glycemic Control in Type 2 Diabetes Subjects: Importance of Interval Length. A Controlled, Counterbalanced, Crossover Study.
Study Goal
The researchers aimed to determine the impact of interval length (3 min vs. 1 min) on postprandial glycemic control following interval walking in individuals with type 2 diabetes.
Results Summary
Interval walking (both 3 min and 1 min cycles) lowered postprandial blood glucose levels compared to no walking, with no significant difference between the two interval lengths. Specific time points during the meal tolerance test showed significant glucose reductions after both interval walking protocols.
Population
Twelve subjects with type 2 diabetes.
Effective Dosage
1-hour interventions with repeated cycles of slow (54% VO2peak) and fast (89% VO2peak) walking, either 3 min/3 min (IW3) or 1 min/1 min (IW1).
Duration
Single bout (1-hour intervention).
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
Interval walking consisting of repeated cycles of 3 min slow and 3 min fast walking (IW3) | decrease | overall mean postprandial blood glucose levels | subjects with type 2 diabetes | 10.3±3.0 vs. 11.1±3.3 mmol/L | resulted in lower | #1 |
Interval walking consisting of repeated cycles of 1 min slow and 1 min fast walking (IW1) | no change | overall mean postprandial blood glucose levels | subjects with type 2 diabetes | 10.5±2.8 mmol/L vs. 11.1±3.3 mmol/L | showed no significant differences | #2 |
Interval walking consisting of repeated cycles of 3 min slow and 3 min fast walking (IW3) | decrease | blood glucose levels at specific time points during the MMTT | subjects with type 2 diabetes | - | differed significantly | #3 |
Interval walking consisting of repeated cycles of 1 min slow and 1 min fast walking (IW1) | decrease | blood glucose levels at specific time points during the MMTT | subjects with type 2 diabetes | - | differed significantly | #4 |
UNLABELLED: Interval-type exercise is effective for improving glycemic control, but the optimal approach is unknown. The purpose of this study was to determine the importance of the interval length on changes in postprandial glycemic control following a single exercise bout. Twelve subjects with type 2 diabetes completed a cross-over study with three 1-hour interventions performed in a non-randomized but counter-balanced order: 1) Interval walking consisting of repeated cycles of 3 min slow (aiming for 54% of Peak oxygen consumption rate [VO2peak]) and 3 min fast (aiming for 89% of VO2peak) walking (IW3); 2) Interval walking consisting of repeated cycles of 1 min slow and 1 min fast walking (IW1) and 3) No walking (CON). The exercise interventions were matched with regards to walking speed, and VO2 and heart rate was assessed throughout all interventions. A 4-hour liquid mixed meal tolerance test commenced 30 min after each intervention, with blood samples taken regularly. IW3 and IW1 resulted in comparable mean VO2 and heart rates. Overall mean postprandial blood glucose levels were lower after IW3 compared to CON (10.3±3.0 vs. 11.1±3.3 mmol/L; P < 0.05), with no significant differences between IW1 (10.5±2.8 mmol/L) and CON or IW3 and IW1 (P > 0.05 for both). Conversely blood glucose levels at specific time points during the MMTT differed significantly following both IW3 and IW1 as compared to CON. Our findings support the previously found blood glucose lowering effect of IW3 and suggest that reducing the interval length, while keeping the walking speed and time spend on fast and slow walking constant, does not result in additional improvements. TRIAL REGISTRATION: ClinicalTrials.gov NCT02257190.