# Effects of running-based versus body-weight-based high-intensity interval training on physical fitness in healthy adolescents

PMID: 36969578
Journal: Frontiers in physiology
Published: 2023
Authors: Li Z, Liu Y, Han X, Zhou Z

## Question

Does running-based HIIT or bodyweight-based HIIT better improve cardiorespiratory fitness, muscle strength/endurance, speed, and physical activity patterns in adolescents?

## Summary

This school-based quasi-experimental study compared running HIIT, bodyweight HIIT, and regular PE in healthy Chinese seventh graders. Both HIIT formats improved cardiorespiratory fitness, strength, and speed, but bodyweight HIIT improved cardiorespiratory fitness more and uniquely improved sit-up endurance. Attendance was high, dropouts were rare, and no injuries were reported.

## Population

- Healthy seventh-grade adolescents from coeducational public middle schools.
- Sample size: 166
- Age: 11-13 years eligible.
- Sex: 71 male and 92 female at enrollment; three later dropouts.
- Fitness level: No regular physical activity other than PE classes within 3 months before the experiment.
- Health status: Healthy adolescents without exercise contraindications, acute illness/injury, psychiatric/psychological disorders, or congenital/acquired heart disease.

## Methodology

- Pre/post quasi-experimental school study with randomized natural classes assigned to R-HIIT, B-HIIT, or control.
- 12 weeks.
- Three public middle schools in Beijing, China; interventions embedded in physical education classes.
- Randomized and controlled study design.

## Protocol

- Bodyweight HIIT.
- Modality: Bodyweight resistance/plyometric exercises.
- Work intervals: 1 minute.
- Recovery: 30 seconds.
- Sets or repetitions: 8-10 intervals.
- Intensity: 75-85% HRmax monitored by heart-rate monitor.
- Session duration: 10-15 minutes including short warm-up, replacing PE warm-up.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.
- Progression: Movement frequency increased after 4 weeks based on participants' improved ability.
- Running HIIT and regular PE control.
- Modality: Running shuttle-based HIIT; control regular PE.
- Work intervals: 1 minute for R-HIIT.
- Recovery: 30 seconds for R-HIIT.
- Sets or repetitions: 8-10 R-HIIT intervals.
- Intensity: 75-85% HRmax for R-HIIT.
- Session duration: 10-15 minutes for R-HIIT embedded in 45-minute PE classes.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.
- Progression: Running audio rhythm accelerated after 4 weeks; control continued regular PE.

## Outcomes

### Cardiorespiratory fitness
Status: improved
Both R-HIIT and B-HIIT improved CRF, with B-HIIT significantly better than R-HIIT.

B-HIIT +4.48 mL/kg/min vs R-HIIT +3.34 mL/kg/min, p<0.05.

### Muscle strength/endurance and speed
Status: improved
Both HIIT groups improved muscle strength and speed; only B-HIIT improved sit-up muscle endurance.

Sit-up endurance improved only in B-HIIT, partial eta squared=0.30, p<0.05.

### Physical activity patterns
Status: improved
On school days, intervention groups had less sedentary/light activity and more moderate/vigorous activity than controls; weekend differences were not significant.

School-day group differences p<0.05; weekend p>0.05.

### Safety/adherence
Status: improved
Attendance averaged above 90%, dropout was low, and no injuries were reported.

Dropout rate 1.81%.

## Practical Insights

- Bodyweight HIIT is highly translatable because it requires little space and no specialized equipment.
- A 1-minute work / 30-second rest structure can improve both aerobic and muscular fitness in adolescents.
- Replacing a PE warm-up with HIIT improved outcomes without reducing school-day activity.

## Limitations

- Quasi-experimental class-level design without full individual randomization.
- Healthy adolescents only; effects in adolescents with obesity are unclear.
- Enjoyment and affective responses were not measured.
- Some selection bias possible because students could refuse participation.
- Accelerometer data were valid for a subsample only.

## Safety And Adherence

- No injuries were reported during the 12-week intervention.
- Participants with exercise contraindications or heart disease were excluded.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/36969578/) (pubmed)
- [DOI](https://doi.org/10.3389/fphys.2023.1060216) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10036788/) (full text)

## Agent Guidance

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