# Comparing the Effectiveness of High Intensity Interval Training vs Continuous Moderate Intensity Exercise on Physical Function Among Older Adults With HIV

PMID: 41583703
Journal: Open forum infectious diseases
Published: 2026 Jan
Authors: Kulik GL, Oliveira VHF, Wilson MP, Khuu V, Jankowski CM, Iriarte E, Davey CH, Cook P, Ghosh D, MaWhinney S, Webel AR, Erlandson KM

## Question

Is HIIT more effective than continuous moderate-intensity exercise for improving physical function in older sedentary adults with HIV when both groups also do resistance training?

## Summary

In sedentary adults age 50 and older with well-controlled HIV, 16 weeks of supervised HIIT plus resistance training improved walking performance and strength, but it was not better than continuous moderate exercise plus the same resistance training. Adherence was high, and serious adverse events were monitored, but this was a clinical population with medical screening.

## Population

- Sedentary adults age 50 and older with virologically suppressed HIV
- Sample size: 111
- Age: Median 57 years, IQR 54-61
- Sex: 14% female
- Fitness level: Sedentary
- Health status: Stable HIV on ART with common cardiometabolic and mental-health comorbidities

## Methodology

- Parallel-group randomized superiority trial
- 16 weeks
- University clinical exercise research sites with supervised training
- Randomized and controlled study design.

## Protocol

- HIIT plus resistance training.
- Modality: Aerobic HIIT plus resistance machines.
- Work intervals: 4 minutes.
- Recovery: 3 minutes at 50% HRR.
- Sets or repetitions: 5 high-intensity bouts.
- Intensity: 90% HRR work bouts.
- Session duration: 42 minutes aerobic plus resistance training.
- Frequency: 3 times/week.
- Program length: 16 weeks.
- Progression: Two-week familiarization, then progressive intensity through week 8.
- Continuous moderate exercise plus resistance training.
- Modality: Walking/jogging or aerobic exercise plus resistance machines.
- Work intervals: Continuous 42 minutes.
- Sets or repetitions: One continuous aerobic bout plus same resistance training.
- Intensity: 60% HRR continuous exercise.
- Session duration: 50 minutes aerobic plus resistance training.
- Frequency: 3 times/week.
- Program length: 16 weeks.
- Progression: Same familiarization and resistance progression; aerobic work remained continuous.

## Outcomes

### Walk time
Status: improved
Both HIIT and CME improved 400-meter walk time, with no significant between-group difference.

HIIT -5.9% and CME -4.6%; between-group p=.33

### Function
Status: improved
Physical-function outcomes improved within groups but HIIT was not superior.

Secondary outcomes showed within-group improvements without significant arm differences.

### Strength
Status: improved
Strength improved in both groups after shared resistance training.

Leg press, bench/chest press, and lateral pulldown improved in both arms.

### Adherence
Status: improved
Visit attendance was high in both arms.

Median 46/48 visits in both groups

## Practical Insights

- For lay users, this supports exercise improving function in a supervised clinical context, not HIIT superiority.
- For generation, long-interval HIIT with 4-minute work and 3-minute recovery can be paired with strength training after familiarization.
- Older clinical populations need screening, AE monitoring, and conservative progression.

## Limitations

- Clinical HIV population limits broad consumer generalization
- Resistance training was included in both arms
- Low female representation
- No evidence that HIIT outperformed continuous moderate exercise

## Safety And Adherence

- Six serious adverse events occurred during the trial period; four unrelated and two related.
- Two related serious adverse events were syncope events; participants resumed exercise after cardiology evaluation and close monitoring.
- One death from pulmonary embolism and pneumonia was considered unlikely study-related.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41583703/) (pubmed)
- [DOI](https://doi.org/10.1093/ofid/ofag002) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12828426/) (full text)

## Agent Guidance

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