# Comparable Effects of High-Intensity Interval Training and Prolonged Continuous Exercise Training on Abdominal Visceral Fat Reduction in Obese Young Women

PMID: 28116314
Journal: Journal of Diabetes Research
Published: 2017
Authors: Zhang H, Tong TK, Qiu W, Zhang X, Zhou S, Liu Y, He Y

## Question

Does work-equivalent HIIT reduce abdominal visceral fat and improve body composition and VO2max as much as prolonged moderate continuous exercise in obese young women?

## Summary

In obese young women, 12 weeks of supervised work-matched cycling HIIT and moderate continuous cycling produced similar reductions in abdominal visceral fat, total fat mass, body fat percentage, and similar VO2max gains. HIIT required much less exercise time, and no adverse events occurred during testing or training.

## Population

- Obese young Chinese women university students.
- Sample size: 43
- Age: 18-22 years eligible
- Sex: Women only
- Fitness level: No regular exercise beyond physical education class
- Health status: Obese; no metabolic, hormonal, orthopedic, or cardiovascular disease

## Methodology

- Randomized controlled trial
- 12 weeks
- Supervised cycle-ergometer exercise training in young women
- Randomized and controlled study design.

## Protocol

- Work-equivalent cycling HIIT.
- Modality: Cycle ergometer.
- Work intervals: 4 min.
- Recovery: 3 min passive recovery.
- Sets or repetitions: Repeated until target energy expenditure.
- Intensity: 90% VO2max.
- Session duration: About 29-38 min for HIIT excluding or including standardized components as reported.
- Frequency: 3-4 sessions/week.
- Program length: 12 weeks.
- Progression: 200 to 300 kJ/session; VO2max retests adjusted workload.
- Moderate continuous cycling.
- Modality: Cycle ergometer.
- Work intervals: Continuous.
- Sets or repetitions: One continuous bout until target energy expenditure.
- Intensity: 60% VO2max.
- Session duration: About 51-74 min across phases.
- Frequency: 3-4 sessions/week.
- Program length: 12 weeks.
- Progression: Same 200 to 300 kJ/session progression and VO2max retesting.

## Outcomes

### Visceral fat
Status: improved
HIIT and MICT similarly reduced abdominal visceral fat area.

HIIT -9.1 cm2; MICT -9.2 cm2; no significant HIIT-MICT difference.

### Subcutaneous fat
Status: improved
HIIT and MICT reduced abdominal subcutaneous fat.

HIIT -35.0 cm2; MICT -28.3 cm2.

### Total fat
Status: improved
Both exercise groups reduced total fat mass and body fat percentage similarly.

Total fat mass -2.8 kg in both groups; body fat percentage -2.5 and -2.4 percentage points.

### VO2max
Status: improved
VO2max improved similarly in HIIT and MICT; control decreased.

HIIT 31.6 to 40.0; MICT 30.6 to 38.3; control 29.3 to 28.0 ml/kg/min.

### Safety
Status: improved
No adverse events occurred during testing or training.

Reported as no adverse events.

## Practical Insights

- HIIT produced similar visceral-fat reduction to much longer MICT when work was matched.
- Time efficiency is the major practical advantage, not superior fat loss.
- Supervision and screening were part of the protocol.

## Limitations

- Women only
- Ages 18-22 only
- Obese but otherwise healthy university students
- No long-term follow-up
- Diet and daily activity were maintained by instruction rather than tightly controlled

## Safety And Adherence

- No adverse events occurred during testing or training.
- Exercise sessions were closely supervised with HR and RPE monitoring.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/28116314/) (pubmed)
- [DOI](https://doi.org/10.1155/2017/5071740) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5237463/) (full text)

## Agent Guidance

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