PMID 36387850

Research
All papers

High-intensity interval training combining rowing and cycling efficiently improves insulin sensitivity, body composition and VO(2)max in men with obesity and type 2 diabetes

Petersen MH, de Almeida ME, Wentorf EK, Jensen K, Ørtenblad N, Højlund K

Question

Does an 8-week supervised HIIT program combining rowing and cycling improve insulin sensitivity, body composition, and VO2max in men with obesity and type 2 diabetes compared with obese and lean glucose-tolerant men?

Summary

This supervised 8-week rowing-and-cycling HIIT study in middle-aged men found improved insulin sensitivity, VO2max, body composition, and selected glycemic markers in men with type 2 diabetes, with similar relative improvements in obese and lean glucose-tolerant men. The trial had excellent adherence and no injuries, but it was not randomized, included only men, and used a highly supervised equipment-based protocol.

Methodology

  • Middle-aged men in lean glucose-tolerant, obese glucose-tolerant, and obese type 2 diabetes groups.
  • 44 participants.
  • Rowing ergometer and cycle ergometer.
  • Work intervals: 1 min high-intensity intervals.
  • Recovery: 1 min active/rest recovery; 4 min break between modality blocks.
  • Intensity: Cycling at 100-110% maximal cycling capacity; HR about 86-88% max.
  • 32-71 min depending on progression phase.
  • 3 sessions/week.
  • 8 weeks.
  • Non-randomized supervised intervention study comparing responses across lean glucose-tolerant, obese glucose-tolerant, and obese type 2 diabetes groups.
  • Insulin sensitivity, Cardiorespiratory fitness, Body composition, and Glycemic biomarkers were tracked.

Outcomes

Insulin sensitivity

Glucose disposal rate improved in all groups, including a large increase in the type 2 diabetes group.

GDR +42% in type 2 diabetes p<0.001, +27% in obese glucose-tolerant p=0.001, +29% in lean p<0.001.

Improved

VO2max

VO2max increased in all metabolic groups.

Approximately +15% in type 2 diabetes (p<0.001), +8% in obese glucose-tolerant (p=0.002), and +10% in lean glucose-tolerant (p=0.001).

Improved

Body composition

Weight, BMI, waist, waist-hip ratio, and fat mass decreased slightly, while lean body mass increased.

Fat mass decreased about 1.6-2.3 kg and lean body mass increased about 0.6-1.5 kg across groups, all p<0.05.

Improved

Glycemic biomarkers in type 2 diabetes

HbA1c and fasting glucose decreased in the type 2 diabetes group.

HbA1c -4 +/- 2 mmol/mol p=0.017; fasting glucose -1.0 +/- 0.4 mmol/L p<0.001.

Improved

Safety and adherence

Adherence was very high and no injuries were reported.

>95% adherence in all groups; no injuries.

Improved

Insights

  • A 1 min on / 1 min off protocol can be progressed by adding blocks, but the late-stage sessions were long for consumer app use.
  • Low-impact equipment-based HIIT may be useful for obesity and diabetes populations under supervision.
  • Do not translate the insulin-sensitivity findings directly to unsupervised bodyweight HIIT.

Limitations

  • Non-randomized design without no-exercise control.
  • Men only.
  • Short intervention and no follow-up.
  • No actual food-intake data.
  • Protocol required rowing/cycling equipment and close supervision.
  • Insulin-treated type 2 diabetes was not included.

Safety

  • No injuries were reported.
  • One lean participant developed knee problems before training and did not complete.
  • The protocol was supervised and HR-monitored.