Salazar-Perez F; Universitat Internacional de Catalunya (UIC), Barcelona, Spain.
Sanz-Santiago V; de Mir-Messa I; Sardon Prado O; et al

European Respiratory Journal. 68(4), 2026 Oct.

BACKGROUND: While high-intensity interval training (HIIT) has shown
effectiveness in improving cardiorespiratory fitness (CRF) across various
chronic respiratory diseases, its impacts on individuals with
post-infectious bronchiolitis obliterans (PIBO) remain unexplored. Our aim
was to assess the effects of a home-based, remotely supervised, HIIT
programme on CRF, clinical and functional variables in patients with PIBO.

METHODS: Participants of this assessor-blinded, multicentre, randomised
controlled trial were individuals with PIBO aged 6-20 years. An exercise
(EXE) group underwent two 40-min sessions of HIIT remotely supervised in
real time per week. Sessions were continued for 16 weeks. The control
(CON) group adhered to general physical activity recommendations. The
primary outcome was peak oxygen uptake (V O2 peak), time to first
ventilatory threshold (VT1), percentage of V O2 at VT1 and ventilatory
equivalent for carbon dioxide, determined via cardiopulmonary exercise
testing on a treadmill. Secondary outcomes were lung function
(spirometry), muscle strength (dynamometry), functional capacity (30-s
sit-to-stand (30s-STS) test), body mass index and St George’s Respiratory
Questionnaire score.

RESULTS: 51 PIBO patients were enrolled (EXE group n=25; CON group n=26)
(49% females; mean+/-sd age 13.3+/-4.2 years; forced expiratory volume in
1 s -3.56+/-1.28 (z-score); V O2 peak 36.8+/-8.6 mL.kg-1.min-1). The HIIT
intervention resulted in improvements in V O2 peak (mean difference 3.39
mL.kg-1.min-1; p=0.04), time to VT1 (mean difference 1.05 min; p=0.04) and
number of repetitions in the 30s-STS test (mean difference 2.21
repetitions; p=0.04). No differences were found in the other variables.

CONCLUSIONS: Our real-time, remotely supervised HIIT intervention was
effective at significantly increasing CRF and functional capacity in
children and adolescents with PIBO.