# Effects of aquatic high-intensity interval training on patient-reported outcome measures and quality-adjusted life-years in adults with rheumatic and musculoskeletal diseases: a secondary analysis of the AquaHigh randomised controlled trial

PMID: 41238358
Journal: BMJ Open
Published: 2025-11-13
Authors: Bunæs-Næss H, Nilsson BB, Kvæl LAH, Heywood SE, Gerritsen RB, Heiberg KE

## Question

Does peer-led aquatic HIIT improve patient-reported outcomes and QALYs more than aquatic moderate continuous training in adults with rheumatic and musculoskeletal diseases?

## Summary

In adults with rheumatic and musculoskeletal diseases, 12 weeks of aquatic HIIT was not statistically better than aquatic moderate-intensity continuous training for patient-reported disease activity, fatigue, pain, health-related quality of life, or QALYs. Both aquatic programs were feasible, and no adverse events were reported.

## Population

- Adults with rheumatic and musculoskeletal diseases in Norway
- Sample size: 89
- Age: Mean 62 years
- Sex: 91% women
- Fitness level: Community clinical exercise participants
- Health status: Doctor-confirmed rheumatic or musculoskeletal diseases

## Methodology

- Secondary analysis of a single-blind parallel randomized controlled trial
- 12-week intervention with 6-month follow-up
- Community aquatic facilities in Eastern Norway
- Randomized and controlled study design.

## Protocol

- AHIIT.
- Modality: Aquatic group exercise.
- Work intervals: 4 min at Borg RPE 14-18.
- Recovery: 2 to 3 min light recovery.
- Sets or repetitions: 4 intervals.
- Intensity: Borg RPE 14-18.
- Session duration: 45 to 60 min.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.
- Progression: Intensity guided by RPE; detailed progression not reported.
- AMICT.
- Modality: Aquatic moderate-intensity continuous class.
- Intensity: Borg RPE 12-13.
- Session duration: 45 to 60 min.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.
- Progression: Usual aquatic class structure.

## Outcomes

### PROMs
Status: no clear change
No statistically significant between-group differences were found for patient-reported outcomes at 3 or 6 months.

All between-group comparisons p>0.05.

### QALYs
Status: no clear change
QALYs were very similar between AHIIT and AMICT.

AHIIT 0.38 versus AMICT 0.37; mean difference 0.012, 95% CI -0.012 to 0.035.

### Safety
Status: improved
No adverse events were reported with either aquatic program.

## Practical Insights

- RPE-guided aquatic HIIT can be feasible in a clinical community setting.
- For clinical aquatic programs, HIIT should be framed as an alternative, not a proven superior option.
- PROMs may improve within groups even when between-group differences are absent.

## Limitations

- Small sample
- Attrition by follow-up
- Mostly women
- Heterogeneous diagnoses
- COVID-19 disruptions
- Self-reported outcomes
- No non-exercise control

## Safety And Adherence

- No adverse events reported by participants or instructors.
- Sixteen COVID-19 infections interrupted training and were equally distributed.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41238358/) (pubmed)
- [DOI](https://doi.org/10.1136/bmjopen-2025-102841) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12625872/) (full text)

## Agent Guidance

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