# Effects of high-intensity interval training combined with dietary intervention on body composition, cardiovascular function, endothelial cell function and blood lipid indexes in children with obesity: a randomized controlled trial

PMID: 41323591
Journal: Frontiers in public health
Published: 2025
Authors: Wang X, Meng Q, Liu T, Lipowski M

## Question

Do MICT, HIIT alone, and HIIT combined with dietary intervention differ in effects on body composition, cardiovascular function, endothelial function, and blood lipids in children with obesity?

## Summary

In children with obesity, 9 weeks of HIIT plus a dietitian-led dietary plan produced larger improvements in adiposity, cardiovascular function, endothelial markers, and several lipids than HIIT alone or moderate continuous training. HIIT alone also improved visceral fat, resting heart rate, cardiac output, vascular resistance, vasodilation capacity, endothelin-1, FMD, LDL, total cholesterol, and triglycerides compared with baseline. Because all groups received active exercise and there was no no-intervention control, the incremental value of HIIT versus natural change is harder to isolate.

## Population

- Children aged 9-12 with obesity/overweight and BMI >=23 kg/m2.
- Sample size: 90
- Age: 10.64 +/- 0.86 years.
- Sex: 45 boys and 45 girls.
- Fitness level: No regular exercise in prior 3 months.
- Health status: Childhood obesity/overweight; severe cardiometabolic or organ dysfunction excluded.

## Methodology

- Randomized three-arm controlled trial comparing MICT, HIIT, and HIIT plus dietary intervention.
- Two-week adaptive training before a 9-week intervention.
- Children hospitalized at the study institution, with exercise on an outdoor/school athletic track supervised by certified instructors and dietitian oversight for the joint intervention.
- Randomized and controlled study design.

## Protocol

- HIIT plus diet / HIIT-only.
- Modality: Running intervals.
- Work intervals: 30-s all-out sprint at 100-120% MAS; article also mentions a 6-min sprint interval.
- Recovery: 30-s active recovery jog at 50% MAS.
- Sets or repetitions: Repeated 10 times with rest between sets.
- Intensity: 100-120% MAS.
- Session duration: Unclear; includes 15-min warm-up and 10-min cool-down.
- Frequency: 4 sessions/week.
- Program length: 9 weeks.
- Progression: Two-week adaptive training.
- MICT.
- Modality: Running.
- Sets or repetitions: Continuous 30-min running.
- Intensity: 60-80% MAS.
- Session duration: 30 min per bout.
- Frequency: Not separately stated, likely same supervised exercise schedule.
- Program length: 9 weeks.
- Progression: Two-week adaptive training.

## Outcomes

### Body composition
Status: improved
All groups reduced BMI, fat content, body fat percentage, and waistline; joint intervention had largest fat and waist improvements.

Most within-group changes p<0.01; joint intervention superior to HIIT for fat content, body fat percentage, and waistline.

### Cardiovascular function
Status: improved
All groups improved HR, cardiac output, and TCR; HIIT and joint intervention improved VDC, with joint intervention greatest.

Joint HR 75.80 to 72.40; CO 5.79 to 8.23; TCR 1390.67 to 971.39; VDC 1.27 to 3.44; p<0.01 and superior to HIIT for several variables.

### Endothelial function
Status: improved
ET-1 and vWF decreased in all groups; FMD and NO improved most clearly in joint intervention and partly in HIIT.

Joint ET-1 91.14 to 66.43; vWF 184.69 to 148.95; FMD 10.70 to 14.24; NO 46.00 to 57.74; p<0.01.

### Lipids
Status: mixed
LDL, total cholesterol, and triglycerides improved most in joint intervention, but HDL decreased in all groups.

Joint LDL 3.66 to 2.84, TC 5.83 to 3.99, TG 3.00 to 2.37, HDL 2.31 to 1.33 mmol/L.

## Practical Insights

- Diet-plus-HIIT evidence should be treated as a combined lifestyle intervention rather than HIIT alone.
- Pediatric high-intensity running needs screening, adaptive training, and certified supervision.
- If citing lipid effects, note that HDL decreased while LDL, total cholesterol, and triglycerides improved.

## Limitations

- No true no-intervention control.
- Short 9-week intervention and no long-term follow-up.
- Sample limited to Chinese children aged 9-12.
- Adherence and adverse-event reporting were sparse.
- Protocol wording leaves exact HIIT set timing unclear.
- Not powered for every secondary endpoint.

## Safety And Adherence

- Severe cardiovascular, endocrine, psychiatric, cardiac, pulmonary, hepatic, and renal dysfunction were excluded.
- Exercise was supervised by certified instructors.
- No explicit adverse-event results were reported.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41323591/) (pubmed)
- [DOI](https://doi.org/10.3389/fpubh.2025.1698573) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12660231/) (full text)

## Agent Guidance

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