PMID 36816767

Research
All papers

Does incorporating high intensity interval training in physical education classes improve fitness outcomes of students? A cluster randomized controlled trial

Jurić P, Dudley DA, Petocz P

Question

Does a 12-week, low-dose HIIT program integrated into physical education improve fitness and adiposity outcomes in 10- to 15-year-old students compared with regular PE?

Summary

This cluster randomized school trial tested adding two 10-minute bodyweight HIIT sessions per week to regular physical education for 12 weeks in Croatian students aged 10-15 years. The intervention improved 20-meter shuttle-run performance, a cardiorespiratory fitness measure, even under intention-to-treat analysis. It did not improve most other Eurofit fitness measures or BMI, and body-fat findings were inconsistent and favored regular PE in the primary analysis.

Methodology

  • Two hundred seven students aged 10-15 years in grades 5-8 from one Croatian school.
  • 207 participants.
  • Bodyweight circuits and 5 m shuttle sprints.
  • Work intervals: 2-minute prep phase plus two 2-minute work phases.
  • Recovery: 30-second passive pulse checks between active phases; 2-minute active recovery at end.
  • Intensity: Maximal exertion during working phases; self pulse target at least 13 beats in 6 seconds.
  • 10 minutes.
  • 2 sessions per week.
  • 12 weeks.
  • Cluster randomized controlled trial with classes allocated to PE plus HIIT or regular PE.
  • Cardiorespiratory fitness, Eurofit fitness battery, Adiposity, and Safety were tracked.

Outcomes

20-meter shuttle run

HIIT improved shuttle-run performance versus regular PE.

p = 0.001, d = 0.31; additional 181.2 m, 95% CI 70.4 to 292.0.

Improved

Intention-to-treat shuttle-run effect

The shuttle-run benefit remained after ITT and missing-data imputation.

ITT p = 0.011, effect 119.6 m; imputation p = 0.003, effect 122.9 m.

Improved

Other Eurofit outcomes

No significant intervention effect was found for balance, coordination, speed, flexibility, power, static strength, muscular endurance, or non-reactive agility.

All listed non-shuttle Eurofit effects p > 0.05.

No clear change

Body composition

BMI outcomes did not improve; body fat percentile findings were inconsistent and unexpectedly favored regular PE in the primary model.

Body fat primary p = 0.025 favoring control; ITT p = 0.086; imputation p = 0.11.

Mixed

Insights

  • A 10-minute bodyweight HIIT block twice weekly can improve schoolchildren's shuttle-run performance.
  • Low-dose bodyweight HIIT should not be expected to improve every fitness domain.
  • Self pulse checks are feasible but less precise than objective intensity monitoring.

Limitations

  • No objective heart-rate assessment.
  • No formal RPE data.
  • No diet or outside physical activity data.
  • Single-school short-term intervention.
  • Body-fat measurement validity concerns.
  • Missing outcome data required ITT and imputation analyses.

Safety

  • No adverse health outcomes were reported.
  • Family doctor health status reports were required.
  • Objective heart-rate monitoring was not used.