PMID 28435687

Research
All papers

An evaluation of low volume high-intensity intermittent training (HIIT) for health risk reduction in overweight and obese men

Kelly BM, Xenophontos S, King JA, Nimmo MA

Question

Do 4 or 6 sessions of low-volume cycle HIIT over 2 weeks improve aerobic capacity, glucose metabolism, body composition, blood pressure, or inflammatory profile in overweight and obese men?

Summary

In a small pilot study of 18 overweight or obese men, 4 or 6 low-volume cycle HIIT sessions over 2 weeks did not significantly improve fasting glucose, insulin sensitivity, aerobic capacity, body composition, blood pressure, or inflammatory markers. The exact workout structure is useful for low-volume HIIT design, but the short duration and no-control design limit conclusions.

Methodology

  • Overweight or obese adult men
  • 18 participants.
  • Cycle ergometer.
  • Work intervals: 1 min at resistance intended to elicit about 90% HRpeak.
  • Recovery: 1 min active recovery at 50 W.
  • Intensity: About 90% HRpeak; cadence 80-100 rpm during work intervals.
  • About 25 min including warm-up and cool-down.
  • 3 sessions/week for 2 weeks.
  • 2 weeks.
  • Small pilot intervention trial comparing two HIIT doses
  • Fasting glucose, Insulin sensitivity, VO2peak, and Body composition were tracked.

Outcomes

Fasting glucose

Neither 4 nor 6 sessions significantly changed fasting glucose.

No significant within-group change reported; p>0.05.

No clear change

Insulin sensitivity

Fasting insulin, OGTT AUC measures, and Matsuda insulin sensitivity did not significantly change.

All glycemic and insulin sensitivity outcomes p>0.05.

No clear change

VO2peak

VO2peak did not significantly improve after either dose.

Group 1 relative VO2peak 35.6 +/- 5.4 to 38.5 +/- 5.4 ml/kg/min, p=0.135; group 2 30.4 +/- 4.2 to 30.5 +/- 3.9 ml/kg/min, p=0.960.

No clear change

Body composition

Body mass, BMI, waist and hip circumferences, and DEXA measures did not significantly change.

No body-composition or anthropometric change reached p<0.05.

No clear change

Inflammation

Measured inflammatory proteins did not significantly change.

Adiponectin, IL-10, TNF-alpha, IL-6, sIL-6R, CRP, and MCP-1 all p>0.05.

No clear change

Insights

  • A 10 x 1-min, 1:1 work-recovery cycling protocol is reproducible and time efficient.
  • Two weeks of 4-6 sessions should not be presented as sufficient evidence for improving cardiometabolic or inflammatory markers.
  • Baseline risk level matters: relatively healthy markers may limit observable change.

Limitations

  • Small pilot sample
  • Male-only sample
  • No nonexercise control group
  • Very short 2-week intervention
  • Participants had relatively healthy baseline glucose, insulin, and inflammatory profiles
  • Session completion and adverse-event reporting were not clearly extracted

Safety

  • Participants were informed of possible risks and discomforts.
  • Adverse events were not reported in the the paper.
  • Eligibility excluded smokers, impaired fasting glucose, diabetes, and BMI >= 40 kg/m2.