Our research studies how HIIT exercise affects heart health in trained athletes by investigating its benefits and limitations as a training method. Short intense workout segments interrupted by recovery breaks push cardiovascular endurance up while making the heart pump stronger and working better while decreasing blood pressure and poor lipid control. HIIT training creates heavy demands on the body that raise the chance of heart troubles and overtraining symptoms. This paper reviews how intense training with recovery periods affects heart health while showing how to keep the cardiovascular system healthy along with athletic success. Research shows that specific HIIT training combined with health assessments helps us get HIIT's benefits safely. HIIT has become popular for fitness training because it delivers better performance results to professional athletes. During HIIT sessions you perform intense exercises in short intervals with recovery breaks to push your cardiovascular system to greater health benefits. Sports experts study HIIT effects on heart health in elite athletes through heart rate variability research and measurements of heart size and working performance. The heart responds positively to frequent HIIT training which improves heart performance by increasing both blood volume and vessel fitness plus raises the heart's pumping ability. Research shows that HIIT helps prevent heart disease through fat reduction and improved metabolism which eases blood pressure concerns and decreases cholesterol levels. Heavy HIIT training with too many repetitions can take a heavy toll on the heart and creates potential heart problems especially when combined with insufficient recovery for athletes. The relationship between workout strength and rest along with an athlete's specific features helps determine when HIIT training becomes more beneficial than dangerous for the heart.