The endurance physical activities proposed for cardiac rehabilitation (CR) widely use mainly training on cyclo-ergometers or treadmill. We hypothesized that soft karate training would be at least as effective as conventional CR programs.

The primary outcome was the maximal O2 consumption (VO2 peak) during a symptom limited cardiopulmonary exercise test at the end of the CR program.

We conducted a single-blind, randomized non-inferiority trial conducted at two centres in patients with Heart Failure (HF) and reduced ejection fraction (HFrEF). Patients were trained in sessions of 1hour/day, 5 days/week using either karate (kicks and punches without combat) or conventional physical training. Patients completed HF quality of life questionnaires: visual analogue score (VAS), Kansas City Cardiomyopathy Questionnaire KCCQ-12 and Depression Anxiety Stress Scale (DASS 21) for depression, anxiety and stress at baseline and at the end of the CR program.

112 patients completed the study (age: 62±12 years, male: 74.1%) and performed an average of 36 sessions. At baseline, peak VO2 was 18.5±5.7ml/kg/min in the karate group and 18.0±6.4ml/kg/min in the conventional group. The VO2 peak was non inferior in the karate group versus the conventional group (non-inferiority limit: 2ml/kg/min, p<0.0001). Therefore, we tested all variables for a superiority hypothesis. At the end of the study both the VO2 peak and the first ventilatory threshold were significantly greater in the karate group than in the conventional group (23.0±7.4 vs. 19.6±6.8ml/kg/min, p<0.0001 and 17.4±5.5 vs. 15.2±4.4, P=0.027 respectively) see Figure 1. The mean values of the VAS, KCCQ12Q and DASS 21 scores were comparable between the 2 groups. No adverse events related to karate training were observed.

Exercise capacity at the end of a cardiac rehabilitation program based on karate training was more improved compared to a conventional program. This type of non-conventional exercise training can therefore be proposed as a safe alternative in HFrEF patients.