PMID 26258597

Research
All papers

High Intensity Interval Training Improves Glycaemic Control and Pancreatic β Cell Function of Type 2 Diabetes Patients

Madsen SM, Thorup AC, Overgaard K, Jeppesen PB

Question

Does 8 weeks of low-volume cycling HIIT improve glycemic control, pancreatic beta-cell function, body composition, and fitness in inactive type 2 diabetes patients and matched healthy controls?

Summary

In inactive older adults with type 2 diabetes and matched healthy controls, 8 weeks of supervised low-volume cycling HIIT improved glycemic control and pancreatic beta-cell-function markers in the diabetes group, and reduced abdominal fat in both groups. The protocol used 10 one-minute cycling intervals three times per week after a warm-up, with one-minute recoveries.

Methodology

  • Inactive type 2 diabetes patients and matched healthy controls
  • 23 participants.
  • Cycle ergometer.
  • Work intervals: 1 minute.
  • Recovery: 1 minute recovery by rest or pedaling at minimum resistance.
  • Intensity: Individual power output eliciting about 90% HRmax.
  • About 30 minutes including warm-up and cool-down.
  • 3 sessions/week.
  • 8 weeks.
  • Non-randomized controlled pre-post exercise intervention
  • Glycemic control, Pancreatic function, Body composition, and Aerobic fitness were tracked.

Outcomes

Glycemia

T2D participants improved fasting glucose, 2-hour OGTT endpoint, and HbA1c.

Fasting glucose p=0.01; 2-hour OGTT endpoint p=0.04; HbA1c p=0.04.

Improved

Pancreatic function

HOMA-IR, HOMA beta-cell function, disposition index, and OGTT glucose continuum improved in T2D.

HOMA-IR p=0.03; HOMA beta-cell function p=0.03; disposition index p=0.03; selected OGTT glucose timepoints p=0.03 to p=0.003.

Improved

Abdominal fat

Abdominal fat mass decreased in both T2D and healthy control groups.

T2D p=0.004, -17.84% +/- 5.02; control p=0.02, -9.66% +/- 3.07.

Improved

Fitness

Absolute and relative VO2max and maximal power output improved after training.

Improved

Safety

The paper reported screening and ECG checks but did not provide explicit adverse-event results for training sessions in the the paper.

Unclear

Insights

  • The 10x1-minute cycling structure is a clear low-volume HIIT template.
  • For type 2 diabetes, translation requires clinical screening and conservative safety messaging.
  • Glycemic claims should be described as promising because the study was small and non-randomized.

Limitations

  • Small sample
  • Non-randomized
  • No non-exercise type 2 diabetes control
  • Clinical exclusions limit generalizability
  • No explicit adverse-event reporting in the paper
  • Sample-flow accounting was not fully clear from the extracted sections

Safety

  • No explicit exercise adverse events were reported in the the paper.
  • Participants with physical-activity contraindications or ECG perturbations were excluded.
  • Resting and post-work ECG showed no signs of ischemia or arrhythmia during VO2max testing in eligible participants.