Background <p>Physical activity (PA) has numerous benefits for heart failure (HF) patients; however, adherence to recommended activity levels remains limited. The engagement in PA may increase with structured exercise programs. This systematic review and meta-analysis aimed to evaluate the effectiveness of exercise-based interventions on PA and related outcomes in patients with HF.</p> Methods <p>A systematic search was conducted across six electronic databases (PubMed, Scopus, Cochrane Library, ScienceDirect, ProQuest, and CINAHL) to identify randomized-controlled trials (RCTs) published in English between 2014 and 2026. Eligible studies were selected according to PICO criteria, and risk of bias was assessed using the ROB-2 Assessment Tool. Jamovi software version 2.3.28 was used to conduct meta-analysis. The random-effects model was used to analyze the pooled standardized mean difference (SMD).</p> Results <p>Eight RCTs met the inclusion criteria for this study. Findings showed that exercise-based interventions investigated a range of outcomes such as PA, functional ability, and quality of life. PA was measured by both objective devices (accelerometers and pedometers) and a validated self-report tool (e.g., International Physical Activity Questionnaire). Meta-analysis demonstrated that exercise-based interventions had a nonsignificant effect on PA (SMD = 0.82; 95%CI –0.13 to 1.78; <i>I</i>^<i>2</i> = 95.63%, <i>p</i> = 0.09) and quality of life (SMD = 0.05; 95%CI –0.41 to 0.51; <i>I</i>^<i>2</i> = 80.51%, <i>p</i> = 0.841). Conversely, a significant effect on functional ability was found (SMD = 0.51; 95%CI 0.14–0.87; <i>I</i>^<i>2</i> = 76.38%, <i>p</i> &lt; 0.001).</p> Conclusion <p>This review found that exercise-based interventions for HF significantly improved functional ability and had nonsignificant effects on PA and QoL in people with HF. However, these findings must be understood with caution due to high heterogeneity and publication bias.</p>