PMID 33160382

Research
All papers

Low-volume high-intensity interval training improves cardiometabolic health, work ability and well-being in severely obese individuals: a randomized-controlled trial sub-study

Reljic D, Frenk F, Herrmann HJ, Neurath MF, Zopf Y

Question

Does low-volume HIIT improve cardiometabolic health, work ability, and well-being in severely obese sedentary employees compared with nutritional counseling alone?

Summary

In obese employees with additional cardiometabolic risk factors, 12 weeks of very low-volume supervised cycling HIIT plus nutrition counseling improved VO2max, exercise performance, waist circumference, blood pressure, work ability, and well-being compared with a nutrition-counseling control group. The protocol took only 14 minutes per session, had high attendance and enjoyment, and reported no adverse events.

Methodology

  • Sedentary employed adults with obesity and cardiometabolic risk
  • 49 participants.
  • Cycle ergometer.
  • Work intervals: 1 min at 80%-95% HRmax.
  • Recovery: 1 min low-intensity recovery.
  • Intensity: 80%-95% HRmax; achieved peak interval HR 94.5 +/- 4.0% HRmax.
  • 14 min.
  • 2 sessions/week.
  • 12 weeks.
  • Randomized controlled trial sub-study
  • VO2max, Waist circumference, Blood pressure, and Work ability and well-being were tracked.

Outcomes

VO2max

HIIT increased absolute and relative VO2max while control declined or did not improve.

No clear change

Waist

Waist circumference decreased significantly only in HIIT.

Improved

Blood pressure

Systolic and diastolic blood pressure improved more with HIIT.

Improved

Lipids/glucose

Glucose, triglycerides, cholesterol fractions, and LDL/HDL ratio did not show meaningful intervention effects.

No clear change

Safety

No adverse events occurred and enjoyment was high.

Unclear

Insights

  • A 14-minute, twice-weekly cycling HIIT format can be enough to improve fitness in sedentary adults with obesity when intensity is verified.
  • Non-weight-bearing modalities are a practical safety and tolerability choice for higher-BMI users.
  • Enjoyment and adherence can be high even in high-risk obesity samples when sessions are brief and supervised.

Limitations

  • Sub-study of a larger trial
  • Non-probability sampling may limit generalization
  • No long-term adherence or efficacy data
  • Supervised cycling setting limits home translation

Safety

  • No adverse events occurred at any time point during training sessions.
  • Authors recommend pre-participation screening for individuals at increased cardiometabolic risk.
  • Authors suggest non-weight-bearing cycling may be better tolerated than running/walking in severe obesity.