# High-intensity interval training can improve hand grip strength, inspiratory muscle, and quality of life in systemic sclerosis subjects

PMID: 33976463
Journal: Reumatologia
Published: 2021-04-27
Authors: Defi IR, Gultom C, Chorman MJ, Jennie J

## Question

Can 12 weeks of supervised HIIT improve functional capacity, inspiratory muscle strength, handgrip strength, and quality of life in people with systemic sclerosis?

## Summary

In 11 women with systemic sclerosis, a 12-week supervised HIIT program improved inspiratory muscle strength, handgrip strength, walking performance/METs, and several quality-of-life symptom scales, while blood pressure and pulse did not significantly change. The study had no control group and was very small.

## Population

- Women with systemic sclerosis receiving routine rheumatology care.
- Sample size: 11
- Age: 40.91 +/- 13.38 years
- Sex: Women only
- Fitness level: Able to exercise; training status unclear
- Health status: Systemic sclerosis with major cardiopulmonary exclusions

## Methodology

- Quasi-experimental single-arm pre-post study
- 12 weeks
- Outpatient clinic gym and gait laboratory

## Protocol

- Systemic sclerosis 30:30 HIIT.
- Modality: Arm crank or cycle ergometer.
- Work intervals: 30 s.
- Recovery: 30 s passive recovery.
- Sets or repetitions: 30-min interval block.
- Intensity: 100% peak power output.
- Session duration: 35 min.
- Frequency: 2 sessions/week.
- Program length: 12 weeks.
- Progression: No explicit progression described.

## Outcomes

### SNIP
Status: improved
Inspiratory muscle strength improved.

45.67 to 54.25 cm H2O, p=0.0041.

### Handgrip
Status: improved
Handgrip strength improved.

13.14 to 15.63 lbs, p=0.0031.

### Walking
Status: improved
Walking performance and METs improved, though table labeling of walking speed/distance is unclear.

Walking measure 184.70 to 246.60, p=0.0039; METs 3.53 to 4.21, p=0.0039.

### SHAQ symptoms
Status: improved
Pain, digestive, pulmonary, Raynaud, digital ulcer, and severity VAS scores improved.

All listed symptom domains p<=0.0051; SHAQ-DI p=0.0571.

### Vitals
Status: no clear change
Blood pressure and pulse did not significantly change.

SBP p=0.8125; DBP p=0.5625; pulse p=0.1275.

## Practical Insights

- Clinical HIIT evidence here is feasibility-oriented and requires supervision.
- 30:30 intervals can be individualized to peak power in a clinic.
- Do not generalize to systemic sclerosis patients with excluded cardiopulmonary complications.

## Limitations

- Very small sample
- No control group
- All women
- Clinical population with exclusions
- No long-term follow-up
- Walking outcome label/value inconsistency

## Safety And Adherence

- No explicit adverse-event list was reported.
- Blood pressure and pulse did not significantly change.
- Participants with ILD, pulmonary arterial hypertension, and NYHA class 3/4 were excluded.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/33976463/) (pubmed)
- [DOI](https://doi.org/10.5114/reum.2021.105454) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8103409/) (full text)

## Agent Guidance

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