Introduction: Physical activity is the voluntary and involuntary movement that activates the respiratory and metabolic functions to produce energy expenditure during activities of daily routine and hobbies. Objective: To know the benefits of physical activity and explain how it is related to the Nursing Systems Theory. Method: Documentary-qualitative design study. Results: The benefits of physical activity can be conceptualized in a cognitive, preventive, and motivational approach. Conclusions: Nursing systems theory clearly shows how nursing care is determined by the level of physical activity and dependence of the patient to carry out daily activities.