Aerobic Fitness Components

Aerobic fitness focuses on strengthening the heart and muscles through a combination of sustained cardiovascular activity, stretching and strength training. Fitness programs are often tailored around current fitness level, fitness goals, schedule and available equipment, as well as health limitations and personal exercise preference. Ideally, aerobic fitness will lead to better function of the circulatory and respiratory systems.

  1. Respiratory Function

    • One of the fundamentals of aerobic fitness is the ability to take oxygen into the lungs. Aerobic exercises emphasize strenuous activity to force the body to take in and transfer oxygen quickly, making the lungs work harder. Much like any other form of exercise, making the lungs work harder strengthens them to take in more oxygen and transfer it faster, allowing the body to handle longer periods of strenuous activity.

    Cardiac Output

    • Much like the respiratory system, aerobic fitness is designed to test the circulatory system -- consisting of the heart, blood vessels and blood -- which carries oxygen through blood to the entire body. Aerobic fitness increases the strength of each pump of the heart, providing a greater push through the vessels. It also improves both the active heart rate (increasing the number of beats per minute during high activity) and the resting heart rate (decreasing the number of beats per minute during periods of rest).

      During aerobic fitness, cardiac output increases as the heart controls the flow of blood throughout the body and muscles by increasing stroke volume (the amount of blood pumped during each heartbeat) and heart rate (the number of heart beats per minute). With the increased cardiac output, more blood is delivered to the working tissues during fitness and exercise.

    VO2 Max

    • VO2 max is a calculation of the amount of oxygen the body can use during strenuous activities such as running, biking, swimming and other aerobic exercises. The number measures the body's oxygen intake (a function of lung capacity) and cardiac strength (heart's ability to effectively pump blood) during such exercises. As aerobic fitness, respiratory function and cardiac output increase, the body's VO2 max will also rise.