# Facilitators influencing participation in digitally-based high-intensity interval training among individuals with axial spondyloarthritis - a qualitative study

PMID: 40931328
Journal: BMC Rheumatology
Published: 2025-09-10
Authors: Torell A, Wiking E, Larsson I, Olsson MC, Haglund E

## Question

What facilitates participation in a digitally supported HIIT program among individuals with axial spondyloarthritis?

## Summary

This qualitative study interviewed 16 people with axial spondyloarthritis who completed a 12-week digitally supported HIIT intervention. Participants said HIIT participation was helped by flexible session design, digital watch/app feedback, individual physiotherapist coaching, social support, perceived health benefits, and growing confidence. Some reported pain, stiffness, technical problems, or frustration when targets were hard to reach, so flexibility and coaching were important.

## Population

- Adults with axial spondyloarthritis from three rheumatology clinics in southern Sweden who completed a digital HIIT intervention.
- Sample size: 16
- Age: Median 47 years, range 28-65
- Sex: 9 female, 7 male
- Fitness level: Met health-promoting physical activity criteria at RCT inclusion; median VO2max 31 ml/kg/min
- Health status: Clinical axial spondyloarthritis population with relatively low median disease activity and function impairment

## Methodology

- Exploratory qualitative interview study nested in the intervention arm of an RCT
- Interviews after a 12-week intervention
- Digital/remote HIIT with rheumatology-clinic recruitment

## Protocol

- Digitally supported HIIT for axial spondyloarthritis.
- Modality: Participant-chosen aerobic HIIT activities guided by a fitness watch and physiotherapist coaching.
- Work intervals: Preset options: 4-minute, 3-minute, or 2-minute intervals.
- Recovery: 2-3 minutes active rest depending on selected preset.
- Sets or repetitions: Options included 4 x 4 minutes, 5 x 3 minutes, or 8 x 2 minutes.
- Intensity: Intervals intended to reach at least 85-90% maximum heart rate.
- Session duration: Participants described sessions around 40-50 minutes including setup/warm-up/recovery.
- Frequency: Two HIIT sessions per week plus one optional aerobic session at at least 75% HRmax for 30 minutes.
- Program length: 12 weeks.
- Progression: Participants could choose and adapt interval plan, activity, time, and location with weekly physiotherapist coaching.

## Outcomes

### Participation facilitators
Status: improved
Participants described intervention design, encouragement, and feelings of well-being as facilitators of participation.

Qualitative categories: intervention design, encouragement, well-being.

### Adaptability and feasibility
Status: improved
Choice of activity, timing, and location made HIIT easier to fit into daily life.

### Digital tools
Status: mixed
Watch/app feedback motivated participants, but technical issues, readability, and connectivity were barriers.

### Coaching and support
Status: improved
Individual coaching, reminders, and social-network support helped participants manage setbacks and continue training.

### Symptoms and safety experience
Status: mixed
Some participants perceived better symptoms and no flare-ups, while others reported increased pain, back pain, or periostitis.

Qualitative symptom reports; adverse-event rates not quantified.

## Practical Insights

- Digital HIIT programs for clinical populations should be adaptable rather than rigid.
- Wearable feedback and remote coaching can help participants learn intensity and persist through setbacks.
- Reminders should be useful but not intrusive.
- Programs should include guidance for illness breaks, pain/stiffness, and returning after missed sessions.

## Limitations

- Qualitative study of participants who all completed the intervention.
- Participants were already physically active enough to meet health-promoting physical activity criteria.
- Findings may not transfer to less motivated or more symptomatic people with axial spondyloarthritis.
- Phone interviews may have shaped disclosure compared with in-person interviews.

## Safety And Adherence

- Some participants reported increased pain, back pain, or periostitis, but flexibility helped them continue.
- Some participants reported no flare-ups and perceived reduced symptoms or medication use.
- The study was not designed to quantify adverse-event rates.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/40931328/) (pubmed)
- [DOI](https://doi.org/10.1186/s41927-025-00567-y) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12421769/) (full text)

## Agent Guidance

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