# Feasibility and safety of high-intensity interval training for the rehabilitation of geriatric inpatients (HIITERGY) a pilot randomized study

PMID: 32503465
Journal: BMC geriatrics
Published: 2020 Jun 5
Authors: Pires Peixoto R, Trombert V, Poncet A, Kizlik J, Gold G, Ehret G, Trombetti A, Reny JL

## Question

Is a supervised HIIT rehabilitation program feasible and safe compared with conventional MICT in geriatric inpatients hospitalized after an acute medical condition?

## Summary

This pilot randomized hospital rehabilitation study compared 2 weeks of HIIT with conventional moderate continuous exercise in geriatric inpatients after acute medical illness. Among patients who were able to start training, HIIT completion was high and no serious adverse events occurred, but 36% of people randomized to HIIT could not begin because they failed or could not complete exercise stress testing. Minor complications, especially osteoarticular pain, were common in HIIT but rarely caused session stoppage.

## Population

- One hundred geriatric inpatients aged at least 65 years hospitalized for rehabilitation after an acute medical condition.
- Sample size: 100
- Age: >=65 years; discussion notes 67-102 years
- Fitness level: Frail inpatient rehabilitation population with low 6-minute walk distance.
- Health status: Post-acute medical hospitalization; unstable conditions, delirium, abnormal EST, and inability to consent or follow instructions excluded.

## Methodology

- Pilot randomized controlled feasibility and safety study in a hospital rehabilitation setting.
- 2-week rehabilitation program.
- Geneva University Hospitals internal medicine, rehabilitation, and geriatrics divisions.
- Randomized and controlled study design.

## Protocol

- HIITERGY HIIT.
- Modality: Adapted hospital rehabilitation exercises, mainly pedal exerciser/NuStep/cycle ergometer.
- Work intervals: 1-minute high-intensity effort.
- Recovery: 1-minute passive rest.
- Sets or repetitions: Repeated intervals during a 30-minute session; exact count not specified in main text.
- Intensity: RPE 8-9/10, reach but not exceed about 95% maxHR.
- Session duration: 30 minutes.
- Frequency: 4 sessions per week.
- Program length: 2 weeks.
- Progression: None reported.
- MICT rehabilitation.
- Modality: Conventional moderate-intensity continuous rehabilitation exercise.
- Work intervals: Continuous exercise.
- Sets or repetitions: One 40-minute group session.
- Intensity: Moderate intensity; heart-rate monitored.
- Session duration: 40 minutes.
- Frequency: 3 sessions per week.
- Program length: 2 weeks.
- Progression: None reported.

## Outcomes

### Feasibility completion
Status: mixed
HIIT completion was low by ITT because many randomized patients could not start, but high among those who completed at least one session.

HIIT ITT 44% (95% CI 30-59), MICT ITT 70% (55-82); HIIT mITT 88% (69-97), MICT mITT 80% (65-90).

### Safety
Status: mixed
No serious adverse events occurred, but minor complications were common, especially osteoarticular pain in HIIT.

Any complication HIIT 64% vs MICT 36%; osteoarticular pain HIIT 40% vs MICT 9%; session stopped due to complication HIIT 4% vs MICT 16%.

### 6-minute walk and gait
Status: improved
Pooled participants improved 6MWT by 23 m and improved several maximum-pace gait parameters; no group trend difference was evident.

Average 6MWT increase 23 m; group x session trends showed no evidence of different evolution between HIIT and MICT.

### Muscle strength
Status: no clear change
No differences in maximum muscular strength were observed between first and last visits.

## Practical Insights

- In frail older adults, feasibility among those who start can be high, but screening failure can be substantial.
- Pedal exerciser, NuStep, and cycle ergometer were most commonly used and appeared suitable for fall-risk patients.
- Pain and dizziness tracking are essential even when serious adverse events are absent.

## Limitations

- Exercise stress testing was only performed in the HIIT group.
- Short 2-week program.
- Feasibility trial not powered for efficacy superiority.
- HIIT required more resources than MICT.
- Hospital logistics caused missed sessions and early exits.

## Safety And Adherence

- No serious adverse events occurred.
- HIIT minor complications included osteoarticular pain, fatigue, dyspnea, dizziness/malaise, muscular pain, one fall/near-fall, and one musculoskeletal lesion.
- Two HIIT participants failed EST, including one with ST-segment modifications and one with blood pressure drop; neither had cardiovascular events during follow-up.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/32503465/) (pubmed)
- [DOI](https://doi.org/10.1186/s12877-020-01596-7) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7275527/) (full text)

## Agent Guidance

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