# High-intensity Interval Training for the Management of Nonalcoholic Steatohepatitis: Participant Experiences and Perspectives

PMID: 37577222
Journal: Journal of Clinical and Translational Hepatology
Published: 2023
Authors: Keating SE, Croci I, Wallen MP, Cox ER, Coombes JS, Burton NW, Macdonald GA, Hickman IJ

## Question

How do people with NASH experience supervised and self-directed HIIT as a management strategy?

## Summary

This qualitative study interviewed adults with biopsy-confirmed NASH who took part in a 12-week supervised 4 x 4 minute HIIT program followed by self-directed HIIT. Participants described initial uncertainty and many medical and time barriers, but those who completed supervised HIIT valued specialist support, felt safer with monitoring, and reported positive functional experiences. Self-directed adherence was harder.

## Population

- Adults with biopsy-confirmed NASH who were physically inactive before trial enrollment.
- Sample size: 12
- Age: 57 +/- 10 years
- Sex: 8 men and 4 women among starters
- Fitness level: Low fitness; mean VO2peak 20.9 +/- 9.1 ml/kg/min
- Health status: NASH with obesity and high cardiometabolic/musculoskeletal comorbidity

## Methodology

- Qualitative interview study nested within a randomized trial
- 12 weeks supervised HIIT plus 12 weeks self-directed HIIT exposure for relevant participants
- University gym supervised by accredited exercise professionals, followed by home/gym/local self-directed exercise
- Randomized and controlled study design.

## Protocol

- Supervised 4 x 4 HIIT for NASH.
- Modality: Primarily treadmill; cycle, rowing, and arm ergometry as needed.
- Work intervals: 4 minutes.
- Recovery: 3 minutes active recovery.
- Sets or repetitions: 4 intervals.
- Intensity: 85-95% HRmax or RPE 15-18.
- Session duration: About 38 minutes including warmup and cooldown at full dose.
- Frequency: 3 days/week.
- Program length: 12 weeks supervised, then 12 weeks self-directed.
- Progression: Build from at least one interval in week 1 to four intervals by week 4.
- Attention-control stretching in parent RCT.
- Modality: Stretching.
- Intensity: Attention-control, not high intensity.
- Program length: Parent trial control phase before crossover.

## Outcomes

### Acceptability
Status: improved
Completers described supervised HIIT positively and valued professional support.

Qualitative themes; no p values

### Adherence
Status: mixed
Supervised attendance was high among completers, but self-directed adherence was poor.

9 completers >90% attendance; 4/12 did not complete full pathway

### Barriers
Status: worse/safety concern
Medical and life barriers frequently interfered with participation.

Qualitative themes

## Practical Insights

- Clinical HIIT programs need screening, support, accountability, and individualized exercise modes.
- Self-directed HIIT after supervised training may require stronger behavior-change supports.
- Participants with NASH may value functional and symptom benefits, not only liver outcomes.

## Limitations

- Qualitative sample was small.
- Exercise trial recruitment may select more willing participants.
- Interviewers were known to participants.
- Non-completer perspectives were limited by dropout.
- No systematic adverse-event table in this qualitative report.

## Safety And Adherence

- The qualitative paper did not provide a systematic adverse-event table.
- Participants were medically screened, cleared, and monitored before and during supervised HIIT.
- Interview data indicated participants felt safer with professional support and monitoring; acute illness was a common reason for missed attendance.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/37577222/) (pubmed)
- [DOI](https://doi.org/10.14218/JCTH.2022.00091S) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10412696/) (full text)

## Agent Guidance

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