# Effects of Different Types of High-Intensity Interval Training (HIIT) on Endurance and Strength Parameters in Children and Adolescents

PMID: 35682437
Journal: International Journal of Environmental Research and Public Health
Published: 2022 Jun 3
Authors: Bossmann T, Woll A, Wagner I

## Question

Do different HIIT formats in school physical education produce different endurance and strength adaptations in children and adolescents?

## Summary

In a school-based randomized trial, 121 students aged 11-15 completed 6 weeks of HIIT in physical education classes. Running 4 x 4, running 12 x 1, and bodyweight circuit HIIT all improved maximal aerobic speed, while the circuit format produced the broadest strength-test improvements.

## Population

- Healthy students in grades 5-8 who completed the required intervention sessions and endurance testing.
- Sample size: 121
- Age: 11-15 years
- Sex: Mixed sex
- Fitness level: General school physical education population
- Health status: Healthy students without musculoskeletal, neurological, or cardiovascular restrictions

## Methodology

- School-based randomized controlled trial with class-level allocation
- 6-week intervention
- Secondary school physical education classes in Baden-Wurttemberg, Germany
- Randomized and controlled study design.

## Protocol

- 12 x 1 minute running HIIT.
- Modality: Running.
- Work intervals: 1 minute.
- Recovery: 40 seconds.
- Sets or repetitions: 12 repetitions.
- Intensity: About 90% of the running speed that could be maintained for 1 minute; students encouraged to work near 90% HRmax.
- Session duration: About 20 minutes after a 3-5 minute warm-up.
- Frequency: 2 physical education sessions per week.
- Program length: 6 weeks, 10-12 sessions.
- Progression: No detailed progression reported.
- 4 x 4 minute running HIIT and bodyweight circuit HIIT.
- Modality: Running or mixed bodyweight circuit.
- Work intervals: 4 minutes for 4 x 4 running; 1 minute for circuit stations.
- Recovery: 3 minutes for 4 x 4 running; 40 seconds for circuit stations.
- Sets or repetitions: 4 x 4 minutes running or 12 x 1 minute circuit stations.
- Intensity: About 90% effort; students encouraged to maintain high intensity.
- Session duration: About 28 minutes for 4 x 4 and about 20 minutes for circuit.
- Frequency: 2 physical education sessions per week.
- Program length: 6 weeks, 10-12 sessions.
- Progression: No detailed progression reported.

## Outcomes

### Main reported result
Status: mixed
Maximal aerobic speed improved significantly in all groups: 4 x 4 running +9.1%, circuit +9.4%, and 12 x 1 running +12.1%.

### Main reported result
Status: no clear change
There was no significant time-by-group interaction for maximal aerobic speed.

### Main reported result
Status: mixed
The circuit group improved all four strength tests.

### Main reported result
Status: mixed
The 12 x 1 group improved lateral side jumps and push-ups, while the 4 x 4 group improved sit-ups only.

### Main reported result
Status: no clear change
Average perceived exertion was about Borg CR 5.4, described as hard, with no significant group differences.

## Practical Insights

- Short school-friendly HIIT blocks can improve aerobic fitness within 6 weeks.
- Bodyweight circuit HIIT may be better than running-only formats when strength and power outcomes are also desired.
- Varied content and music were identified as useful for motivation in physical education.

## Limitations

- Students were randomized by class rather than individually by fitness level.
- Heart rate was not reliably monitored, so achievement of the intended 90% HRmax intensity is uncertain.
- Outcomes used field tests rather than laboratory measures.
- There was no non-HIIT usual-PE control group.

## Safety And Adherence

- All included students completed at least 10 sessions; adverse events were not described in the extracted full text.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/35682437/) (pubmed)
- [DOI](https://doi.org/10.3390/ijerph19116855) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9180911/) (full text)

## Agent Guidance

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