Aims: Exercise training (ET) is an effective therapy in heart failure with preserved ejection fraction (HFpEF), but the influence of different ET characteristics is unclear. We aimed to evaluate the associations between ET frequency, duration, intensity [% heart rate reserve (%HRR)] and estimated energy expenditure (EEE) with the change in peak oxygen consumption (V̇O2) over 3 months of moderate continuous training (MCT, 5×/week) or high-intensity interval training (HIIT, 3×/week) in HFpEF.
Methods and results: ET duration and heart rate (HR) were recorded with a smartphone application. EEE was calculated using the HR data during ET and the individual HR-V̇O2 relationships during cardiopulmonary exercise testing. Differences between groups and associations between ET characteristics and peak V̇O2 change were assessed with linear regression analyses. Peak V̇O2 improved by 9.2 ± 13.2% after MCT and 8.7 ± 15.9% after HIIT (P = 0.67). The average EEE of 1 HIIT session was equivalent to ∼1.42 MCT sessions and when adjusted for EEE, the mean difference between MCT and HIIT was -0.1% (P = 0.98). For both MCT and HIIT, peak V̇O2 change was positively associated with ET frequency (MCT: R2 = 0.103; HIIT: R2 = 0.149) and duration/week (MCT: R2 = 0.120; HIIT: R2 = 0.125; all P < 0.05). Average %HRR was negatively associated with peak V̇O2 change in MCT (R2 = 0.101; P = 0.034), whereas no significant association was found in HIIT (P = 0.234). Multiple regression analyses explained ∼1/3 of the variance in peak V̇O2 change.
Conclusion: In HFpEF, isocaloric HIIT and MCT seem to be equally effective over 3 months. Within each mode, increasing ET frequency or duration/week may be more effective to improve peak V̇O2 than increasing ET intensity.
Keywords: Diastolic heart failure; Duration; Energy expenditure; Exercise capacity; High-intensity interval training; Intensity.
In heart failure with preserved ejection fraction, endurance exercise training is one of the most effective treatment options to improve exercise tolerance, however, the influence of different exercise training characteristics such as training frequency, duration, intensity and energy expenditure have not yet been evaluated. A high-intensity interval training session of 38 min was associated with a ∼42% higher energy expenditure compared with a moderate continuous training session of 40 min. After taking into account the different energy expenditure, both training modes had equal effects on exercise tolerance. Therefore, patient preferences should be considered when planning an exercise program to improve treatment adherence. A higher number of exercise sessions per week or a higher weekly duration of exercise were more closely related to an increase in exercise tolerance than a higher exercise intensity. Therefore, increasing the frequency or weekly duration of exercise may be more effective in improving exercise tolerance than increasing exercise intensity.
© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.