Feasibility and Tolerance of High-Intensity Interval Training in Adults With Cystic Fibrosis

Objectives: To assess the feasibility and the tolerance of a high-intensity interval training (HIIT) program compared with conventional rehabilitation during a 3-week hospital stay in adults with cystic fibrosis (CF) and to analyze the effectiveness and impact on health indicators of HIIT. Design: A prospective, 2-center, open-label, randomized, controlled study. Setting: Cystic Fibrosis Resource and Expert Centers, Roscoff and Giens (France). Participants: A total of 62 adults (aged: 36.1±11y; M/F ratio: 1.3) with CF were included. Interventions: Intervention group performed 3 HIIT sessions, alternating 30 seconds of work and 30 seconds of rest repeated 6 times ≥80% of maximum heart rate, and 2 low-intensity sessions per week. Control group (conventional rehabilitation) performed 5, 20-to-30-minute sessions per week at the first aerobic ventilatory threshold. Main Outcome Measures: (1) Feasibility was evaluated by compliance; (2) tolerance by the degree of dyspnea and adverse effects; (3) effect on physical capacity using the 6-minute walk, body composition, the forced expiratory volume in 1 second (FEV1), and the multidimensional dyspnea profile; (4) impact on health indicators by the Fibrosis Quality of Life Questionnaire and the Hospital Anxiety and Depression; and (5) participant satisfaction by the STARFISH (perception of physical activity) and the Physical Activity Enjoyment Scale. However, tolerance was lower in those with severe respiratory impairment and those without cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy. Effectiveness on physical capacity (6-minute walk test, muscle strength, and FEV1) and quality of life was similar between the training methods. Conclusions: HIIT is feasible, safe, and well tolerated and could be used as a timesaving alternative to conventional treatment, particularly in people under CFTR modulator therapy.