# Effects of HIIT and MICT on visceral fat and carotid hemodynamics in obese adults

PMID: 36186829
Journal: Journal of exercise science and fitness
Published: 2022 Oct
Authors: Shi W, Chen J, He Y, Su P, Wang M, Li X, Tang D

## Question

How do HIIT and MICT affect visceral fat indicators and carotid hemodynamic parameters in obese young adults?

## Summary

In young men with obesity, 8 weeks of supervised HIIT or moderate continuous exercise improved several body-composition and carotid blood-flow measures compared with a non-exercise control. The HIIT protocol details were only partly described in text, limiting translation.

## Population

- Male obese college-aged adults
- Sample size: 52
- Age: Approximately 18-22 years; group means about 20.8-21.4 years
- Sex: 52 men
- Fitness level: Sedentary/no structured exercise in previous 3 months
- Health status: BMI >=30 kg/m2; non-smokers; no vasoactive medication; PAR-Q screened

## Methodology

- Prospective controlled exercise trial with randomized exercise groups and separately recruited control group
- 8 weeks
- Supervised exercise sessions with laboratory vascular assessment
- Randomized and controlled study design.

## Protocol

- HIIT circuit.
- Modality: High-intensity interval/circuit exercise.
- Sets or repetitions: Text states gradual increase across 3 stages; exact interval prescription not available in text.
- Intensity: 80-95% HRmax.
- Session duration: 10-30 min.
- Frequency: 3-4 sessions/week.
- Program length: 8 weeks.
- Progression: Gradual increase across 3 stages; exact stage details in figure rather than extractable text.
- MICT and non-exercise control.
- Modality: Moderate aerobic exercise or health education control.
- Work intervals: Continuous exercise for MICT.
- Sets or repetitions: One continuous 45 min aerobic bout plus warm-up and relaxation.
- Intensity: 60-70% HRmax for MICT.
- Session duration: 55 min for MICT.
- Frequency: 3-4 sessions/week for MICT.
- Program length: 8 weeks.
- Progression: MICT program changed from running/aerobic exercises to include bodyweight strength plus aerobic work in weeks 5-8.

## Outcomes

### Body fat
Status: improved
Fat mass, body fat percentage, waist circumference, and LAP improved in the exercise groups.

FM/BF%/WC decreased in HIIT and MICT; LAP decreased HIIT p < 0.01 and MICT p < 0.05

### Blood velocity
Status: improved
Blood velocity and wall shear stress increased after HIIT and MICT.

Blood velocity and WSS increased after HIIT/MICT, p < 0.01

### Carotid indices
Status: improved
HIIT improved several carotid hemodynamic markers, including lower oscillatory shear and arterial stiffness.

HIIT OSI decreased 0.15 to 0.09, p = 0.001; arterial stiffness 4.04 to 3.28, p = 0.001; circumferential strain increased 0.11 to 0.13, p = 0.02

### HIIT vs MICT
Status: mixed
HIIT and MICT were broadly similar, with OSI differing between exercise groups.

ANCOVA showed HIIT vs MICT difference only for OSI, p < 0.01

## Practical Insights

- Both high- and moderate-intensity supervised exercise may improve vascular flow markers in young men with obesity.
- The article does not provide enough text detail to reproduce the HIIT circuit precisely.
- Carotid hemodynamic outcomes are mechanistic and not directly user-facing.

## Limitations

- Men only
- Young obese adults only
- Small non-randomized control group
- Diet not strictly controlled
- HIIT protocol not fully reproducible from text

## Safety And Adherence

- Participants were screened with PAR-Q and recent medical reports/ECG-related safety checks; frequent absences and adherence issues led to exclusions, but adverse events were not emphasized.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/36186829/) (pubmed)
- [DOI](https://doi.org/10.1016/j.jesf.2022.09.001) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9486563/) (full text)

## Agent Guidance

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