Guidelines recommend exercise training as part of rehabilitation for individuals with heart failure, but what type of exercise is most beneficial?
In our article, Why Everyone Is Talking About VO2max as the Ultimate Longevity Marker, we discuss VO2max and peak VO2. These metrics indicate the maximum/peak volume of oxygen your body can take in, transport, and utilize during intense exercise. It’s a marker of fitness, but more importantly, it’s a critical marker of healthspan.
VO₂max is also prognostic in individuals with cardiovascular disease. It is widely used in cardiac rehabilitation because of its strong association with clinical outcomes across multiple cardiovascular conditions.
In this article, we aim to provide a snapshot of some of the research that evaluated exercise programs in individuals with heart disease and heart failure, and how effective they were at improving metrics of cardiac health and peak V̇O2.
In a small study of patients who had a myocardial infarction (heart attack) that resulted in heart failure, peak V̇O2 increased more with aerobic interval training than moderate continuous training (46% versus 14%, P<0.001) and was associated with reverse heart remodeling (the heart recovers a shape that more efficiently pumps blood). Their ejection fraction (a measure of heart function in pumping blood) increased 35%, and pro-brain natriuretic peptide improved by 40% (a lab marker of heart failure). 1
The FITR Heart Study demonstrated a 10% improvement in cardiorespiratory fitness with high intensity interval training (HIIT) versus 4% with moderate intensity continuous training (MICT) after 4 weeks of cardiac rehabilitation in patients with coronary artery disease cleared for exercise.2 Interestingly, both groups showed comparable 12-month outcomes (10% vs. 7% improvement), underscoring that long-term adherence may narrow short-term performance differences.
A 2025 meta-analysis of 21 randomized controlled trials in patients with heart failure found that HIIT produced superior improvements in peak VO₂ compared to moderate-intensity continuous training (MICT). Mean difference in peak VO₂ was 1.19 mL/kg/min, alongside meaningful gains in six-minute walk distance and left ventricular ejection fraction (how efficiently the heart pumps oxygenated blood throughout the body).
Notably, even in patients with heart failure, HIIT showed only a marginally greater improvement in peak VO₂ compared to MICT – suggesting that while intensity still favors HIIT, the gap narrows considerably in the setting of compromised cardiac function. That being said, exercise plan should be tailored to the individual, by qualified healthcare provider team, and resistance training should be incorporated to support lean muscle mass.10
The 2024 AHA Core Cardiac Rehabilitation Update takes into account the benefits of moderate intensity training and HIIT. It recommends a frequency of at least 3-5 aerobic sessions per week of moderate to vigorous intensity (40-89% of HR reserve), after evaluation, in addition to 2-3 non-consecutive strength-training days per week, after evaluation.3 Evaluation, exercise prescription and supervision should be determined by a qualified treatment team, as part of a program. Speak to your cardiologist if you believe that you may be a candidate.
Seeking Personalized Care
To learn more about our medical, nutrition, and health coaching services, contact us
at 646.627.8000, fill out [this form] for a complimentary discovery call, or email