Major systems influenced by regular exercise include the cardiovascular, musculoskeletal, and nervous systems. Regular physical activity strengthens the heart and improves circulation, enhancing overall cardiovascular health. Muscle and bone strength are increased through resistance training, reducing the risk of injuries and osteoporosis. Additionally, exercise positively affects the nervous system by improving brain function, boosting mood, and enhancing cognitive abilities. Overall, a holistic approach to exercise benefits both physical and mental health across various bodily systems.