Feasibility of high-intensity interval training in older adults with HIV and co-occurring hypertension
Question
To assess the feasibility, efficacy, and safety of a 6-week HIIT intervention among older people living with HIV and co-occurring hypertension.
Summary
This single-group pilot study tested whether older adults living with HIV and treated hypertension could complete a 6-week, supervised cycling HIIT program. Ten of 13 enrolled participants completed the study. Attendance was high, prescribed high-intensity heart-rate targets were achieved by completers, and no serious adverse events were reported. Blood pressure, BMI, perceived exercise barriers, SPPB score, and 4-meter walk time moved in favorable directions, while 6-minute walk distance declined slightly. Because the study was small, uncontrolled, and designed for feasibility rather than efficacy, the results mainly support feasibility and safety in a supervised clinical exercise setting.
Methodology
- Older people living with HIV and co-occurring treated hypertension, inactive at baseline, recruited from a local HIV/AIDS clinic.
- 13 participants.
- Upright stationary bike.
- Work intervals: 4 min at 80-90% age-predicted HRmax.
- Recovery: 3 min active rest at about 60-70% HRmax.
- Intensity: 80% HRmax progressing to 90% HRmax over 6 weeks; RPE monitored.
- Up to 45 min including 5-min warm-up and 5-min cool-down.
- 2 sessions per week.
- 6 weeks.
- Single-group pre-post pilot feasibility intervention study
- Feasibility, Exercise perceptions, Blood pressure, and Body mass index were tracked.
Outcomes
Feasibility
Of 26 eligible participants contacted, 13 consented and enrolled; 10 completed the study. Consent rate was 50%, completion was 76.9%, attendance was 86%, and protocol adherence to high-intensity bouts was 100% among completers.
Descriptive feasibility outcomes only.
Exercise perceptions
EBBS total increased from 135 to 139; Benefits Subscale increased from 94 to 95; Barriers Subscale decreased from 29 to 26.
Hedges' g: total EBBS 0.2, Benefits 0.1, Barriers 0.4.
Blood pressure
Systolic BP declined from 133.4 +/- 9.0 to 128.1 +/- 9.9 mmHg; diastolic BP declined from 80.2 +/- 6.5 to 76.0 +/- 8.6 mmHg.
Systolic difference -5.3 mmHg (95% CI -12.8 to 3.0), Hedges' g 0.5 (95% CI -0.4 to 1.4); diastolic difference -4.2 mmHg (95% CI -11.7 to 2.0), Hedges' g 0.5 (95% CI -0.4 to 1.4).
BMI
BMI declined from 33.3 +/- 12.4 to 32.3 +/- 10.8 kg/m2.
Difference -1.0 kg/m2 (95% CI -3.1 to 1.1), Hedges' g 0.1 (95% CI -0.9 to 0.8).
6-minute walk test
6MWT distance declined from 419.7 +/- 80.4 to 414.7 +/- 51.6 m.
Difference -5.0 m (95% CI -9.7 to 1.0), Hedges' g 0.1 (95% CI -0.8 to 0.9).
Safety
One participant experienced foot pain during exercise sessions; no serious adverse events were reported.
Insights
- A 4 x 4-min cycling HIIT structure twice weekly can be feasible in carefully screened, supervised older adults with HIV and treated hypertension.
- Clinical safety evidence from this study depends on supervision, screening, and heart-rate monitoring.
- Fatigue, travel distance, time commitment, and pain are important implementation barriers for this population.
- The 6MWT decline cautions against assuming all fitness markers improve after a short HIIT program in older PWH.
Limitations
- Small sample size
- Single-group pre-post design
- No randomization or control group
- Single-center recruitment from one HIV clinic
- Pilot study not powered or designed for efficacy testing
- Limited generalizability to broader HIV populations or unsupervised settings
- Mechanistic vascular outcomes were not assessed
Safety
- One foot-pain event occurred during exercise sessions.
- No serious adverse events were reported.
- The study used screening, supervised exercise, continuous heart-rate monitoring, and progressive intensity ramping.