PMID 29114503

Research
All papers

Effects of long or short duration stimulus during high-intensity interval training on physical performance, energy intake, and body composition

Alves ED, Salermo GP, Panissa VLG, Franchini E, Takito MY

Question

Do long and short HIIT work intervals with the same work-to-rest ratio produce different effects on body composition, aerobic power, energy intake, hunger, and perceived exertion in untrained women?

Summary

In 20 previously untrained young women, 6 weeks of cycling HIIT using either 15 longer one-minute intervals or 45 shorter 20-second intervals produced similar improvements in estimated VO2max and body composition. Neither protocol changed body mass, hunger perception, or energy intake, and perceived exertion declined across the training period.

Methodology

  • Previously untrained young women
  • 20 participants.
  • Cycle ergometer.
  • Work intervals: 1 min at 90% HRmax.
  • Recovery: 30 s active recovery at 60% HRmax.
  • Intensity: 90% predicted HRmax work; 60% HRmax recovery.
  • 15 min effort/recovery plus 3-min warm-up and 3-min cooldown.
  • 3 sessions/week.
  • 6 weeks.
  • Quasi-experimental two-group intervention study
  • Estimated VO2max, Body composition, Energy intake, and RPE and hunger were tracked.

Outcomes

Fat mass

Fat mass and fat percentage decreased over time in both HIIT groups.

Improved

VO2max

Estimated VO2max increased in both groups.

Improved

Energy intake

Energy intake did not change and did not differ between groups.

No clear change

RPE

RPE decreased across training sessions with no group difference.

Improved

Insights

  • When total high-intensity time and work:rest ratio are matched, short and long interval formats may be interchangeable for early adaptations.
  • RPE can improve with repeated exposure even while workload rises.
  • Short-term HIIT did not increase hunger or reported energy intake in this sample.

Limitations

  • Small sample
  • Female-only young adult sample
  • Quasi-experimental design and no non-exercise control group
  • Estimated VO2max rather than direct gas exchange
  • Adherence and adverse events not reported

Safety

  • The article did not report adverse events, injuries, or dropouts.
  • Heart rate and RPE were monitored during sessions.