Final answer:
Aerobic exercise increases HR and CO to meet the body's demands, within a target heart rate range, while resistance exercise involves significant short-term increases in BP to supply stressed muscles. The responses differ due to the specific physiological demands and adaptations of each exercise type.
Step-by-step explanation:
The responses of heart rate (HR) and blood pressure (BP) to aerobic and resistance exercise differ due to their distinct physiological demands on the body. Aerobic exercise, such as running or swimming, is characterized by sustained, rhythmic movements and mostly leads to an increase in HR and a proportional increase in cardiac output (CO) to meet the heightened oxygen and nutrient demands of the body. However, there is a target heart rate range to maintain optimal benefits and avoid overexertion, as very high HR may decrease CO due to reduced stroke volume (SV) from decreased ventricular filling time during diastole.
Resistance exercise, on the other hand, involves brief and intense exertions as seen in weightlifting. During such exercise, BP increases significantly to supply the temporarily stressed muscles with oxygen and nutrients. Unlike aerobic exercise, resistance training does not typically result in sustained high HR, but it may cause more significant short-term increases in BP.
The different responses can be attributed to the unique physiological adaptations taking place. Aerobic exercise promotes endurance and increases the efficiency of oxygen usage in the body, while resistance exercise primarily enhances muscular strength and size. Both types of exercise induce beneficial adaptations in the cardiovascular system; however, the adaptations in each system are specific to the type of exercise performed.