Long-term adaptations of the cardiorespiratory system

Long-term Adaptations of the Cardiorespiratory System

Increased Stroke Volume and Cardiac Output

• Stroke volume refers to the amount of blood pumped by each ventricle of the heart per beat. With long-term exercise, it increases.
• An increased stroke volume leads to a greater cardiac output, which is the volume of blood pumped by the heart per minute.
• This means the heart becomes more efficient at circulating blood throughout the body, improving your body’s ability to transport oxygen to and remove waste from your muscles.

Lower Resting Heart Rate

• Regular exercise often results in a lower resting heart rate.
• This occurs because your heart becomes more efficient and can pump more blood per beat, so it doesn’t need to beat as fast when you’re at rest.
• A lower resting heart rate can indicate better cardiovascular fitness.

Increased Maximal Oxygen Uptake (VO2 Max)

• Maximal Oxygen Uptake (VO2 max) is the maximum capacity of the body’s muscles to take in, transport, and use oxygen during exercise.
• Long-term exercise can improve VO2 max, leading to better aerobic endurance and overall fitness.
• This enables a person to sustain high-intensity activities for longer periods of time.

Increased Number of Capillaries

• Continued exercise leads to capillarisation, the increase in the size and number of capillaries surrounding the muscle fibres.
• This enhances the muscles’ capacity to receive an increased flow of oxygen and nutrients and increases removal of waste products, allowing for greater endurance and faster recovery.

Improved Respiratory Efficiency

• With regular exercise, the muscles involved in the act of breathing—intercostal muscles and diaphragm—become stronger.
• This facilitates increased volume and efficiency in the process of breathing, allowing for a greater amount of air to be used during respiration and hence more oxygen available for the working muscles.
• Over time, this adaptation can lead to improved performance in endurance-based activities by reducing breathlessness.

Understanding these adaptations can help improve performance in sports and exercise, and is key to understanding how an athlete’s body prepares itself for increased demands and how training programmes can be designed for maximum benefit.