During exercise, several physiological changes occur within the body to accommodate increased demands. Heart rate and breathing rate rise to enhance blood flow and oxygen delivery to muscles. As a result, muscle temperature increases, improving enzyme activity for better performance. Blood vessels dilate (vasodilation), prioritizing oxygen-rich blood to active tissues. Hormonal levels also fluctuate, particularly with the release of endorphins, which can improve mood and decrease pain perception. These adaptations enhance overall fitness, allowing for increased endurance, strength, and efficiency in movement during physical activity.