# High-Intensity Interval Training Reduces Liver Enzyme Levels and Improves MASLD-Related Biomarkers in Overweight/Obese Girls

PMID: 39796598
Journal: Nutrients
Published: 2025 Jan 1
Authors: Abassi W, Ouerghi N, Hammami MB, Jebabli N, Feki M, Bouassida A, Weiss K, Knechtle B

## Question

Does 9 weeks of HIIT improve liver enzymes and other MASLD-related biomarkers in overweight or obese adolescent girls?

## Summary

Thirty-three overweight or obese adolescent girls completed a 9-week randomized trial of school-based running HIIT or control. The HIIT group improved body composition, systolic blood pressure, maximal aerobic speed, ALT, AST, lipids, glucose, insulin resistance, and HDL-C, while the control group did not change. Training adherence was not recorded, but no injuries occurred.

## Population

- Overweight or obese adolescent girls from secondary schools.
- Sample size: 33
- Age: 17.0 +/- 1.15 years
- Sex: Girls only
- Fitness level: Usual activity was weekly two-hour physical education lessons
- Health status: BMI >=95th percentile for age; no contraindication to physical activity

## Methodology

- Nine-week randomized controlled trial
- 9 weeks
- Secondary schools in the Kef region of Tunisia
- Randomized and controlled study design.

## Protocol

- Running HIIT.
- Modality: Running.
- Work intervals: 30 seconds at 100-105% MAS.
- Recovery: 30 seconds active recovery at 50% MAS.
- Sets or repetitions: Two series of 6 repetitions, progressed after week 4.
- Intensity: 100-105% MAS.
- Session duration: Not fully reported; includes 15 min warm-up and 15 min cool-down.
- Frequency: 3 sessions/week.
- Program length: 9 weeks.
- Progression: Repetitions increased from week 4; intensity increased from week 7.
- Control.
- Modality: Regular physical education only.
- Session duration: Weekly two-hour physical education lessons as usual activity.
- Program length: 9 weeks.

## Outcomes

### Liver enzymes
Status: improved
ALT and AST decreased in the HIIT group and did not change in controls.

ALT p=0.013, ES=0.47; AST p=0.012, ES=0.58.

### Insulin resistance
Status: improved
HOMA-IR decreased in the HIIT group and did not change in controls.

HOMA-IR p=0.010, ES=0.47.

### Body composition and SBP
Status: improved
Body mass, BMI, body fat, waist circumference, and systolic blood pressure improved in the HIIT group.

Body mass p<0.001; BMI p=0.001; BF p<0.001; WC p=0.003; SBP p=0.011.

### Uric acid and platelets
Status: no clear change
Uric acid and platelet indexes did not significantly change.

## Practical Insights

- Thirty-second running intervals may be practical for adolescent school settings with supervision.
- Claims about MASLD should be framed as biomarker improvement, not confirmed liver fat reversal.

## Limitations

- Small sample
- Girls only
- No liver fat imaging
- Diet not controlled
- Exercise adherence not recorded

## Safety And Adherence

- No injuries occurred.
- Exercise adherence was not recorded.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/39796598/) (pubmed)
- [DOI](https://doi.org/10.3390/nu17010164) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11723383/) (full text)

## Agent Guidance

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