Moderate-intensity continuous exercise is superior to high-intensity interval training in the proportion of VO2peak responders after ACS

Introduction and objectives: We compared the effects of 12 weeks of low-volume high-intensity interval training (LV-HIIT) vs moderate-intensity continuous exercise training (MICET) on cardiopulmonary exercise test parameters and the proportion of non/low responders (NLR) to exercise training in post-acute coronary syndrome (ACS) patients. Methods: Patients with a recent ACS were randomized to LV-HIIT, MICET, or a usual care group. LV-HIIT consisted of 2 to 3 sets of 6 to 10 minutes with repeated bouts of 15 to 30 seconds at 100% of peak workload alternating with 15 to 30 seconds of passive recovery. Cardiopulmonary exercise test parameters were assessed, and key exercise variables were calculated. Training response was assessed according to the median VO2peak change post vs pretraining in the whole cohort (stratification NLR vs high response). Results: Fifty patients were included in the analysis (LV-HIIT, n = 23; MICET, n = 18; usual care, n = 9) and 74% were male. The proportion of NLR was higher in the LV-HIIT group than in the MICET group (LV-HIIT 61%, MICET 21%, and usual care 80%; P = .0040). VO2peak-dependent variables (VO2peak, percent-predicted VO2peak) improved in both training groups (P = .002 and P < .0001 for time with LV-HIIT and MICET, respectively), but the improvement was more pronounced with MICET (P = .004 and P = .001 for interaction, respectively). The Delta VO2/Delta workload slope improved only with MICET (P = .021). Conclusions: In patients with a recent ACS, several prognostic VO2peak-dependent variables were improved after LV-HIIT, but the improvement was more pronounced or only found after MICET. Low-volume HIIT resulted in a higher proportion of NLR than isocaloric MICET. (C) 2019 Sociedad Espanola de Cardiologia. Published by Elsevier Espana, S.L.U. All rights reserved.