Heart failure affects more than 64 million people worldwide (1%–3% in the general adult population) and its prevalence is projected to increase. This condition is commonly categorized into 2 main types: heart failure with reduced ejection fraction (HFrEF; where the heart is too weak to pump enough blood to meet the body's needs) and heart failure with preserved ejection fraction (HFpEF; where the heart becomes stiff and cannot relax sufficiently to fill with enough blood). Regardless of type, heart failure is a life-threatening condition characterized by low exercise tolerance, progressive functional decline, reduced health-related quality of life (HRQoL), and a high risk of hospitalizations, morbidity, and mortality. The study led by Tasuku Terada was published online on March 23, 2026, in the Journal of Sport and Health Science .
Previous studies have shown that aerobic training and resistance training independently improve aerobic fitness, walking distance, muscle strength, and HRQoL. Some studies have also demonstrated superior benefits of high-intensity interval training (HIIT) on aerobic fitness and cardiac function in patients with heart failure when compared to traditionally used moderate-intensity continuous training. However, despite the well-established benefits of each exercise modality, the effects of combining aerobic training and muscle strength training (i.e., combined training) compared to the routinely recommended aerobic training alone were not clear in patients with heart failure. In this study, the researchers compared the effects of combined training and aerobic training alone on aerobic fitness, muscle strength, and HRQoL in patients with heart failure. These comparisons were made while accounting for heart failure classifications (i.e., HFrEF or HFpEF), total exercise duration (i.e., matched or unmatched exercise session duration between combined and aerobic training alone), and exercise type (e.g., HIIT).
The researchers systematically searched databases for studies directly comparing the effects of combined training and aerobic training alone on aerobic fitness, walk test distance, muscle strength, and HRQoL in patients with heart failure. Of 13,965 studies they screened, 15 studies were included (466 patients with HFrEF (89%) and 60 with HFpEF (11%); 17% female). Pooled analyses showed that, in HFrEF, combined training increased aerobic fitness, walk test distance, and upper body muscle strength more than aerobic training alone. The superior effects of combined training on aerobic fitness and walking distance were retained when exercise session duration was matched between the two exercise modalities, indicating that combined training has a greater impact on these measures independent of total exercise duration. HIIT combined with muscle strength training also increased aerobic fitness more than HIIT alone. No differences were found between combined and aerobic training alone in lower body muscle strength or HRQoL. Overall adherence to combined training was high or comparable to that of aerobic training alone. Similarly, dropout rates in the combined training group were comparable to those in aerobic training alone, and no notable differences in the risk of adverse events were observed.
To summarise, in predominantly male patients with HFrEF, combined training yielded greater improvements in aerobic fitness, walking distance, and upper body muscle strength than aerobic training alone. These results highlight that, when prescribing exercise for a fixed time frame, allocating time to both aerobic training and muscle strength training may be a more effective strategy for improving aerobic fitness in patients with HFrEF. Additionally, because HIIT may improve aerobic fitness more effectively while requiring less time than moderate-intensity continuous training, combining HIIT with muscle strength training may offer a time-efficient approach to improve aerobic fitness in patients with HFrEF. Considering the absence of notable differences in adherence or adverse events, these findings support that replacing part of aerobic training with muscle strength training may be an effective strategy for patients with HFrEF to increase aerobic fitness, walking distance, and muscle strength, all of which are important predictors of better prognosis in patients with heart failure. Further evidence is needed to clarify the effects of combined training in HFpEF.
