PMID 38746000

Research
All papers

Eight weeks of high-intensity interval vs. sprint interval training effects on overweight and obese adolescents carried out during the cool-down period of physical education classes: randomized controlled trial

González-Gálvez N, Soler-Marín A, Abelleira-Lamela T, Abenza-Cano L, Mateo-Orcajada A, Vaquero-Cristóbal R

Question

Do 8 weeks of school-based SIT or HIIT improve body composition, blood pressure, pulse rate, cardiorespiratory fitness, and enjoyment in adolescents with overweight or obesity?

Summary

This randomized school trial compared two 12-minute interval protocols performed during physical education cooldowns in adolescents with overweight or obesity. Both SIT and HIIT improved fat percentage and trunk fat mass, but the 2-minute HIIT protocol improved more outcomes, including lean mass, blood pressure, pulse rate, and estimated VO2max. Enjoyment improved in both exercise groups.

Methodology

  • Adolescents with overweight or obesity from a high school in Spain.
  • 45 participants.
  • Running.
  • Work intervals: 3 x 2 minutes.
  • Recovery: 2 minutes between work intervals.
  • Intensity: 80% HR reserve work / 50% HR reserve rest in weeks 1-4, progressing to 85% / 55% in weeks 5-8.
  • 12 minutes.
  • 2 sessions/week.
  • 8 weeks.
  • Randomized controlled school trial with SIT, HIIT, and regular physical education control groups.
  • Body composition, Blood pressure and pulse rate, Cardiorespiratory fitness, and Enjoyment were tracked.

Outcomes

Body composition

Both SIT and HIIT improved fat mass percentage and trunk fat mass; HIIT also improved lean mass.

Adjusted analysis: SIT trunk FM change -0.8 kg, p=0.001; HIIT trunk FM change -0.6 kg, p=0.005; HIIT lean mass increased, reported significant.

Improved

Blood pressure, pulse rate, and VO2max

HIIT improved BP variables, pulse rate, and VO2max, whereas SIT did not significantly improve these outcomes.

Adjusted HIIT changes: BP -13.4 mmHg p=0.013; SBP -12.4 mmHg p=0.044; DBP -14.0 mmHg p=0.019; PR -10.5 bpm p=0.002.

Improved

Enjoyment

Enjoyment during activity improved in both SIT and HIIT groups.

Authors report an improvement in enjoyment in participants who performed both protocols.

Improved

Insights

  • A 12-minute 3 x 2-minute HIIT module can fit into school PE cooldown time.
  • In this sample, longer 2-minute high-intensity bouts were more useful than 1-minute SIT for BP and fitness.
  • Enjoyment can improve even with high-intensity training when sessions are short and embedded in school routines.

Limitations

  • Small final sample.
  • Maturational status was not assessed.
  • Weight status was classified by BMI rather than fat-mass measures.
  • Sex effects were adjusted but sample size prevented sex-stratified conclusions.
  • Adverse events and attendance were not clearly reported.

Safety

  • No explicit adverse-event results were found in the paper.
  • Pathology-based exclusions were used before participation.