Imagine yourself lined up against your competitors, waiting for the starting gun to fire. You may feel your heart beating faster and your breath quickening just imagining this scenario. Most people experience an increase in breathing before exercise. This is known as the anticipatory rise in breathing and occurs for good reason.
Control Over Ventilation
Your body needs to maintain a constant flow of oxygen into and carbon dioxide out of your bloodstream. If this does not occur, your blood pH reduces which may become dangerous. There are two mechanisms your body relies on to control your breath before, during and after exercise. These are neural and humoral control.
Anticipatory Breathing
Your breathing rate increases before exercise as a response to a signal sent to your respiratory muscles by the brain. In the minutes before exercise, the neural command center over ventilation increases your breathing rate. This occurs as a means of preparation of the exercise you are about to do.
Neural Control
The motor cortex of your brain relays information to the medulla which then carries out the lung function. The medulla consists of two separate areas: the expiratory and inspiratory centers. During inspiration, the medulla signals to your inspiratory muscles to fire and then they relax when done. The same occurs with the expiratory center.
Breathing Rates
The body is quite an amazing machine, capable of doing almost anything you ask it to. During rest your breathing rate is about 12 breaths per minute equaling about 6 l per minute of air. During exercise, this can increase to 48 breaths per minute, moving 192 l of air. This is a change of 32 times the amount at rest.
References
- "Exercise Physiology"; George A. Brooks, Thomas D. Fahey, Kenneth M. Baldwin; 2005
- "Advanced Physical Education and Sport"; John Honeybourne; 2002
