PMID 36291490

Research
All papers

The Relative Importance of Age at Peak Height Velocity and Fat Mass Index in High-Intensity Interval Training Effect on Cardiorespiratory Fitness in Adolescents: A Randomized Controlled Trial

Domaradzki J, Koźlenia D, Popowczak M

Question

Do biological age and baseline fat mass index influence cardiorespiratory-fitness gains after a 10-week school-based HIIT intervention in adolescent boys and girls?

Summary

In a secondary-school sample, a 10-week Tabata-style HIIT program embedded in physical education improved Harvard Step Test fitness-index changes more than control. The analysis focused on whether biological maturity and baseline fat mass explained who improved; HIIT had a positive effect, age at peak height velocity mattered especially in girls, and baseline fat mass did not mediate the effect.

Methodology

  • First-year secondary-school adolescents who completed a school HIIT project and were analyzed for positive CRF response.
  • 141 participants.
  • Bodyweight/calisthenic Tabata exercises.
  • Work intervals: 20 seconds maximum-intensity exercise.
  • Recovery: 10 seconds rest; 1 minute between 4-minute sessions.
  • Intensity: Maximum intensity/as many repetitions as possible; intensity verification described in prior project papers.
  • 14 minutes of HIIT within a PE lesson.
  • 1 session per week.
  • 10 weeks.
  • Secondary analysis of a randomized school-based controlled HIIT project using path analysis.
  • Fitness index, Body composition, and Maturity were tracked.

Outcomes

Fitness index

Fitness-index changes were positive in all groups but much greater in HIIT groups.

Mean delta FI: EG boys 3.01, EG girls 1.88, CG boys/girls about 0.35; EG vs CG F=10.21, p=0.002.

Improved

HIIT path effect

HIIT directly and positively affected FI changes in the whole sample and in both sexes.

Whole group beta=0.246, p=0.002; boys beta=0.313, p=0.018; girls beta=0.223, p=0.026.

Improved

Maturity

Age at peak height velocity was related to FI change overall and was close to significant in girls but not boys.

Whole group APHV beta=-0.270, p=0.035; girls beta=-0.193, p=0.053; boys beta=-0.135, p=0.311.

Mixed

Fat mass mediation

Baseline fat mass index did not mediate the relationship between HIIT, biological age, sex, and FI changes.

Whole group FMI to delta FI beta=0.107, p=0.244; indirect effects p=0.532 and p=0.268.

No clear change

Insights

  • Brief Tabata sessions can fit a 45-minute PE lesson.
  • Adolescent response to HIIT may vary by sex and maturity status.
  • Baseline fat mass alone should not be used to predict CRF gains from school HIIT.

Limitations

  • Single secondary school.
  • Sex distribution and experimental/control group sizes were uneven.
  • No continuous heart-rate monitoring.
  • No monitoring of daily activity or nutrition.
  • CRF was estimated with Harvard Step Test fitness index rather than direct VO2max.
  • Adverse events and adherence were not reported.

Safety

  • Students with medical contraindications were excluded.
  • Heart rate was not continuously monitored during intervention.
  • The article did not report adverse events or injuries.