The transition from childhood to puberty involves profound physiological transformations that significantly impact the cardiovascular system. As biological maturation progresses, mainly driven by hormonal changes, both structural and functional adaptations occur in the heart and blood vessels. The heart increases in size and mass, particularly the left ventricle, allowing for a greater pumping capacity to meet the growing body’s metabolic demands. Simultaneously, the vasculature adapts through changes in diameter and elasticity, improving the regulation of blood flow and arterial pressure. Functionally, this stage is marked by a gradual enhancement of cardiovascular efficiency: resting heart rate tends to decrease, stroke volume increases, and autonomic nervous system control becomes more balanced. These changes support improved physical performance. Additionally, sex-specific differences begin to emerge during puberty, reflecting the distinct influence of sex hormones on cardiovascular physiology. Understanding the cardiovascular changes that occur during puberty is essential not only for accurately characterizing normal physiological development but also for identifying early deviations that may be associated with an increased risk of cardiovascular disease later in life. In this context, physical exercise plays a pivotal role. Regular physical activity during childhood and adolescence not only accompanies the biological maturation process but also acts as a key modulator of the hemodynamic, metabolic, and autonomic mechanisms underlying cardiovascular remodeling. Through its influence on variables such as cardiac output, blood pressure, baroreflex sensitivity, endothelial function, and autonomic tone, exercise helps shape a more efficient cardiovascular profile that is better equipped to withstand future physiological and pathological challenges.