# Prevalence of Positive Effects on Body Fat Percentage, Cardiovascular Parameters, and Cardiorespiratory Fitness after 10-Week High-Intensity Interval Training in Adolescents

PMID: 35336798
Journal: Biology
Published: 2022-03-10
Authors: Domaradzki J, Koźlenia D, Popowczak M

## Question

How often do adolescents show positive changes in body fat percentage, blood pressure, and cardiorespiratory fitness after a 10-week school-based HIIT program, and do sex or BMI status modify those patterns?

## Summary

In a school physical education study, 141 adolescents completed 10 weeks of either standard PE or one weekly 14-minute bodyweight Tabata-style HIIT session inside PE. The HIIT group showed more frequent positive changes in systolic blood pressure and fitness index than controls, while body fat percentage findings were mixed and sex/BMI patterns suggested boys, especially lower-BMI boys, responded more often.

## Population

- Secondary-school adolescents completing PE-based intervention or control PE.
- Sample size: 141
- Age: Approximately 16 years.
- Sex: 52 boys and 89 girls.
- Fitness level: School pupils; additional sports training excluded.
- Health status: Medical contraindications excluded.

## Methodology

- Class-randomized controlled school physical education intervention.
- 10 weeks
- Secondary-school physical education lessons.
- Randomized and controlled study design.

## Protocol

- PE HIIT.
- Modality: Bodyweight Tabata-style exercise.
- Work intervals: 20 s.
- Recovery: 10 s, plus 1 min between three Tabata sessions.
- Sets or repetitions: Three Tabata sessions using pushups/high knees, dynamic lunges/spider crawling, and plank-to-pushups/side squeezes.
- Intensity: Target 75-80% HRmax; achieved mean HR 156.2 +/- 17.8 bpm.
- Session duration: 14 min HIIT within a 45 min PE lesson.
- Frequency: 1 session/week.
- Program length: 10 weeks.
- Progression: No progression reported.
- Standard PE.
- Modality: Usual school physical education.
- Session duration: Standard PE lesson duration.
- Frequency: School PE schedule.
- Program length: 10 weeks.

## Outcomes

### Positive changes
Status: mixed
HIIT had more positive SBP and fitness-index responders than control, but body-fat responder prevalence was higher in controls.

EG positive changes: BFP 60.27%, SBP 83.56%, DBP 64.38%, FI 73.97%; CG: BFP 70.59%, SBP 38.24%, DBP 70.59%, FI 52.94%.

### Blood pressure
Status: improved
HIIT increased prevalence of favorable systolic blood pressure change and was reported to affect BP responder patterns.

SBP positive change: EG 61/73 vs CG 26/68.

### Fitness index
Status: improved
HIIT increased prevalence of favorable fitness-index change.

FI positive change: EG 54/73 vs CG 36/68.

### Sex and BMI
Status: mixed
Boys and lower-BMI boys appeared more responsive; girls less often showed linked FI/BFP improvements.

The authors used log-linear analysis, MCA, and clustering to describe sex/BMI-dependent patterns.

## Practical Insights

- A 14-minute screen-guided bodyweight HIIT block can fit into a PE lesson.
- Responder prevalence may be a useful framing because not all adolescents improve on all outcomes.
- Avoid promising body-fat improvements from this protocol; the control group also improved.

## Limitations

- No maturation-stage control.
- No nutrition control.
- No follow-up after the 10-week intervention.
- Harvard Step Test instead of direct VO2max.
- Once-weekly HIIT dose.

## Safety And Adherence

- No adverse effects were observed.
- Ten pupils were excluded for medical contraindications before participation.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/35336798/) (pubmed)
- [DOI](https://doi.org/10.3390/biology11030424) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8945095/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.