Objectives: HIV is associated with reduced cardiorespiratory fitness (CRF), a strong predictor of future cardiovascular events and mortality. Supervised exercise training programs improve CRF, but the ideal exercise training intensity is unknown among PWH. We hypothesized that high-intensity interval training (HIIT) would result in greater improvements in CRF than continuous moderate-intensity exercise (CME) without increased risk of adverse events among older sedentary adults with HIV. Methods: We conducted a multicenter randomized clinical trial of people ages 50 years and older with treated, virally-suppressed HIV, self-reported fatigue, and sedentary lifestyle. Participants were randomized 1:1 to 16 weeks of supervised HIIT or CME. Cardiopulmonary exercise testing (CPET) using a treadmill graded exercise protocol was performed prior to randomization and at 16 weeks to assess CRF, measured as peak oxygen consumption (VO 2 ). CPETs were interpreted blinded to treatment assignment. The trial was preregistered at ClinicalTrials.gov NCT04550676. Results: Among 212 PWH screened, 142 consented, 127 completed baseline CPET, 118 were randomized (110 with adequate quality CPET): 54 to HIIT and 56 to CME. Median age was 56.5 years, 12% female, and 44% were obese (BMI ≥30). At baseline, absolute peak VO 2 was 2.3 L/min and relative to body weight was 25 ml/kg/min (91% predicted peak VO 2 ). In the intention-to-treat analysis adjusted for age, sex, and site, assignment to HIIT was associated with a 0.14 L/min greater increase in absolute peak VO 2 from baseline to 16 weeks compared to CME (95% CI 0.01 to 0.27, p =0.03) and a 1.60 ml/kg/min greater increase in relative peak VO 2 (95% CI 0.23 to 2.97; p =0.023). Results were consistent in unadjusted and per-protocol analyses. Six serious adverse events (SAEs) occurred during the 16-week intervention: 4 unrelated (including 1 death), 2 related (both syncope) in the CME arm; participants were evaluated by cardiology and resumed exercise without further SAEs. There were more nonserious AEs in the HIIT group (40 versus 22 in CME group), mostly mild-moderate musculoskeletal injuries. Conclusions: Among older sedentary people with HIV, HIIT is associated with a greater improvement in CRF assessed with CPET compared to CME, without a greater risk of serious adverse events. Exercise recommendations for aging people with HIV should consider the greater cardiopulmonary benefit of HIIT compared to CME.
Durstenfeld et al. (Tue,) studied this question.