Exercise tolerance varies significantly with age and fitness level. Generally, younger individuals tend to have higher exercise tolerance due to better cardiovascular function, muscle strength, and recovery capacity. As people age, physiological changes, such as decreased muscle mass and cardiovascular efficiency, can lead to diminished endurance and strength, affecting their ability to perform physical activities. Conversely, individuals with a high fitness level often exhibit greater exercise tolerance, regardless of age, due to their improved conditioning and recovery ability. Tailoring exercise programs to accommodate these variations is essential for maximizing performance and safety.