Increased respiratory rate is one of the most obvious adaptations you make to meet the demands of exercise. The rate of blood flow and gas exchange throughout the pulmonary system will increase during exercise to supply sufficient amounts of oxygen as well as remove excess carbon dioxide.
Respiratory Physiology
As multicellular organisms with a closed circulatory system, our body has mechanisms to absorb and deliver oxygen to cells and tissues, while simultaneously removing waste products including carbon dioxide. During exercise, the respiratory system will adjust its function to support increased rates of oxygen consumption and carbon dioxide production. This response prevents dramatic shifts in blood pH and temperature, both important variables in biochemical reactions throughout the body.
Tachypnea
Tachypnea, an increased breathing rate, is one of the body's crucial responses to exercise. As muscle cells produce carbon dioxide, the acidity of the blood leaving your muscles will increase. This change in blood pH is detected by the central nervous system, which compensates by increasing the respiratory rate. A condition known as hypoventilation, characterized by slow or shallow breathing, will produce dangerous increases in blood acidity, highlighting the importance of tachypnea in controlling blood pH during exercise.
Respiratory Rate
At rest, most people have a respiratory rate of 15 to 20 breaths per minute. With exercise, these rates will increase; the precise frequency of respiration depends on the type of exercise and the athlete's fitness level.
Variations in Pulmonary Response to Exercise
Scientists have learned about the lungs during exercise by studying the lungs of patients with various respiratory disorders. Conditions such as asthma show the importance of airways that are capable of adjusting their diameter under different circumstances. For instance, during exercise, your respiratory airways dilate to allow increased rates and volumes of respiration. This does not happen in exercise-induced asthma, often leading to difficulty breathing during exercise. Use of a bronchodilator before exercise or different medications prescribed by your doctor can help alleviate this condition.
References
- DeGowin's Diagnostic Examination: Vital Signs, Anthropometric Data, and Pain; Richard LeBlond et al.; 2010
- MayoClinic.com: Exercise-Induced Asthma; Mayo Clinic Staff; March 2010
- Evolve: Normal Ranges and Averages
