# Effects of high intensity interval training on sustained reduction in cardiometabolic risk associated with overweight/obesity. A randomized trial

PMID: 35401768
Journal: Journal of Exercise Science & Fitness
Published: 2022
Authors: Mendelson M, Chacaroun S, Baillieul S, Doutreleau S, Guinot M, Wuyam B, Tamisier R, Pépin JL, Estève F, Tessier D, Vergès S, Flore P

## Question

How do moderate continuous training, fixed-recovery HIIT, and self-modulated-recovery HIIT compare for fitness, cardiometabolic risk, and longer-term continuation in overweight or obese adults?

## Summary

In 60 overweight or obese adults, 8 weeks of supervised cycling HIIT improved cardiorespiratory fitness and waist circumference more than moderate continuous cycling. Four months after supervision ended, the fixed-recovery HIIT group showed better preservation of fitness and more favorable changes in total and abdominal fat and total cholesterol-to-HDL ratio, but HIIT did not clearly improve long-term exercise continuation compared with moderate training.

## Population

- Non-active adults with overweight or obesity and no insulin-treated diabetes or major heart or respiratory disease
- Sample size: 60
- Age: Mean 54 +/- 11 years
- Sex: 19 female, 41 male
- Fitness level: Non-active, reporting less than 2 hours of low-intensity physical activity per week
- Health status: Adults with overweight or obesity; BMI 31.5 +/- 2.8 kg/m2

## Methodology

- Single-blind randomized controlled trial with three exercise arms
- 8 weeks supervised training plus 4-month autonomous follow-up
- Hospital-based supervised exercise program with post-program autonomous follow-up
- Randomized and controlled study design.

## Protocol

- Fixed-recovery cycling HIIT.
- Modality: cycle.
- Work intervals: 60 seconds.
- Recovery: 60 seconds.
- Sets or repetitions: Participants completed 45-minute cycling sessions with 22 bouts of 1 minute at 100% peak power output separated by 1 minute passive recovery. A second HIIT arm used the same work bouts but allowed recovery to vary from 30 seconds to 2 minutes.
- Intensity: 100% peak power output during work intervals.
- Session duration: 45 minutes.
- Frequency: 3 sessions per week.
- Program length: 8 weeks supervised training plus 4-month autonomous follow-up.
- Progression: Week 1 progressed toward the full 22-bout session.
- Moderate continuous cycling.
- Modality: cycle.
- Sets or repetitions: Participants cycled continuously for 45 minutes at 50% peak power output, close to maximal fat oxidation.
- Intensity: 50% peak power output.
- Session duration: 45 minutes.
- Frequency: 3 sessions per week.
- Program length: 8 weeks supervised training plus 4-month autonomous follow-up.
- Progression: Week 1 progressed toward the full 45-minute session.

## Outcomes

### VO2peak
Status: improved
HIIT and self-modulated HIIT increased VO2peak more than MICT after the supervised program.

Effect: +14% to +17%; Favours: intervention

### Threshold power
Status: improved
HIIT arms improved power at ventilatory thresholds and maximal fat oxidation more than MICT.

Effect: About +25%; Favours: intervention

### Waist circumference
Status: improved
HIIT arms reduced waist circumference compared with MICT.

Effect: -1.53 cm; Favours: intervention

### Follow-up fitness
Status: unclear
At four-month follow-up, fixed-recovery HIIT better preserved cardiorespiratory fitness than MICT.

Favours: intervention

### Exercise continuation
Status: no clear change
Reported physical-activity continuation did not significantly differ between MICT, HIIT, and self-modulated HIIT.

Effect: 68% MICT, 59% HIIT, 47% self-modulated HIIT; Favours: no_difference

## Practical Insights

- For supervised cycling programs, 1-minute intervals at 100% peak power output can improve fitness efficiently in overweight or obese adults.
- Allowing participants to self-modulate recovery did not clearly improve later exercise continuation.
- Benefits during supervised HIIT may not translate automatically into better long-term adherence.

## Limitations

- No non-exercise control group.
- Missing accelerometer follow-up data and sensor issues limited physical-activity conclusions.
- Dietary survey limitations.
- Findings need confirmation in more deconditioned populations.

## Safety And Adherence

- The authors described excellent adherence and tolerance to high-volume short-interval HIIT.
- Detailed adverse-event counts were not found in the extracted full text.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/35401768/) (pubmed)
- [DOI](https://doi.org/10.1016/j.jesf.2022.03.003) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8956941/) (full text)

## Agent Guidance

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