Exercise stimulates a two-phase increase in breathing (pulmonary ventilation).
At the commencement of exercise, there is an almost immediate, marked increase in breathing. This initial increase is due to body movement. As the body moves, the part of the brain controlling movement (the motor cortex) becomes more active. This then sends stimulatory impulses to the part of the nervous system which controls breathing, and the respiratory rate increases.
This initial sharp rise is followed by a more gradual rise in the rate and depth of breathing, relative to the level of exertion. This second-phase increase is brought about by temperature and chemical changes in arterial blood. As we exercise, the increased metabolism of muscles produces more heat, carbon dioxide and acidic atoms (H+). This is sensed by chemical receptors which again stimulate the inspiratory centre to increase breathing which facilitates the binding of H+ and bicarbonate and the removal of carbon dioxide. This helps the body to maintain homeostasis and ensure it continues to work efficiently.
In addition, during exercise, the diaphragm and intercostal muscles work harder, increasing the expansion of the thoracic cavity which in turn increases the expansion of the lungs, and draws more air into the lungs, increasing the tidal volume.
This ventilatory response to exercise is proportional to the intensity of exercise. More intense exercise, causes a sharper initial rise in breathing, and a higher secondary phase. This is because higher intensity exercise requires greater metabolism, so the increase in breathing is directly proportional to the body’s metabolic requirements. The increased breathing required for low intensity exercise may be accomplished simply by taking a bigger breath (ie increasing your tidal volume). However, higher intensity exercise not only requires a bigger breath, but also an increased respiratory rate to meet the body's demands.
At the conclusion of exercise, the energy requirements of the muscles decrease quickly to resting levels. However, breathing recovery back to normal levels is somewhat slower. This is likely because post-exercise, the lungs are assisting the body to regulate temperature, pH balance, and pCO2 levels.
These changes in both the cardiovascular and respiratory systems combine to deliver substantially more blood to the working muscles, and return more used blood to the lungs. This allows more oxygen and nutrients to be delivered to meet the increase in metabolic needs, and it also allows for more carbon dioxide and waste products, such as H+ ions to be dispersed so they do not build up in the body, inhibiting performance. Furthermore, body temperature is regulated even though more heat is being generated by the working muscles, and this means the body can work efficiently, without temperatures reaching dangerous levels which could cause heat exhaustion or heat stroke.
This initial sharp rise is followed by a more gradual rise in the rate and depth of breathing, relative to the level of exertion. This second-phase increase is brought about by temperature and chemical changes in arterial blood. As we exercise, the increased metabolism of muscles produces more heat, carbon dioxide and acidic atoms (H+). This is sensed by chemical receptors which again stimulate the inspiratory centre to increase breathing which facilitates the binding of H+ and bicarbonate and the removal of carbon dioxide. This helps the body to maintain homeostasis and ensure it continues to work efficiently.
In addition, during exercise, the diaphragm and intercostal muscles work harder, increasing the expansion of the thoracic cavity which in turn increases the expansion of the lungs, and draws more air into the lungs, increasing the tidal volume.
This ventilatory response to exercise is proportional to the intensity of exercise. More intense exercise, causes a sharper initial rise in breathing, and a higher secondary phase. This is because higher intensity exercise requires greater metabolism, so the increase in breathing is directly proportional to the body’s metabolic requirements. The increased breathing required for low intensity exercise may be accomplished simply by taking a bigger breath (ie increasing your tidal volume). However, higher intensity exercise not only requires a bigger breath, but also an increased respiratory rate to meet the body's demands.
At the conclusion of exercise, the energy requirements of the muscles decrease quickly to resting levels. However, breathing recovery back to normal levels is somewhat slower. This is likely because post-exercise, the lungs are assisting the body to regulate temperature, pH balance, and pCO2 levels.
These changes in both the cardiovascular and respiratory systems combine to deliver substantially more blood to the working muscles, and return more used blood to the lungs. This allows more oxygen and nutrients to be delivered to meet the increase in metabolic needs, and it also allows for more carbon dioxide and waste products, such as H+ ions to be dispersed so they do not build up in the body, inhibiting performance. Furthermore, body temperature is regulated even though more heat is being generated by the working muscles, and this means the body can work efficiently, without temperatures reaching dangerous levels which could cause heat exhaustion or heat stroke.