Regular exercise leads to various adaptations and many pathophysiological changes that significantly benefit exercise stamina and overall health, both in the general population and in patients with chronic cardiovascular diseases. High-intensity interval training (HIIT) is a form of exercise training that consists of short repetitive bursts of intense workouts that push the body to more than 90 percent of its maximal oxygen consumption (VO2 max) and more than 75 percent of maximal power, with in between periods of low-intensity exercise for recovery, followed by a cool-down period. HIIT has unquestionably emerged as a powerful and effective intervention in rehabilitating patients, particularly those recovering from heart attacks and strokes. HIIT significantly enhances cardiovascular fitness by improving parameters such as VO2 max, endothelial function, and overall cardiac output. In addition to these cardiovascular benefits, HIIT also contributes to improved metabolic health, including better glycemic control and lipid profile regulation, which are often compromised in patients with cardiovascular conditions. Furthermore, HIIT has a positive impact on stroke patient's functional recovery and quality of life, allowing them to regain mobility, independence, and a sense of well-being more quickly. While concerns about the safety of high-intensity exercises in individuals with compromised heart function remain, current evidence suggests that when properly supervised, HIIT is both safe and well-tolerated in these populations. As healthcare continues to evolve, the incorporation of innovative and evidence-based approaches such as HIIT may redefine the future of cardiovascular rehabilitation, ultimately providing long-term health benefits for patients recovering from MI and stroke.