Age affects cardiovascular fitness as physiological changes lead to reduced muscle mass, metabolism, and heart efficiency. Generally, younger individuals maintain higher levels of cardiovascular endurance due to better oxygen uptake and less wear on the body. As people age, they may experience a decline in maximum heart rate and aerobic capacity, often requiring tailored exercise regimens to improve fitness. However, regular and appropriate exercise can mitigate these effects and promote healthy aging, demonstrating that while age impacts fitness, proactive measures can sustain cardiovascular health.