INCREASING OXYGEN UPTAKE DURING REST AND PHYSICAL EXERCISE
This can be applied to all sports and the benefits experienced in life in general.
Tidal volume: the normal volume of air entering the lungs during one inhale at rest.
Respiratory rate: the number of breaths per minute.
Minute ventilation: the volume of air that enters the lungs over one minute.
RR * TV= MV
With each breath you take, approximately, 150ml remains in the nasal cavity, throat and the rest of the breathing passages, this air remains in “dead space” as no gas exchange can be made from this air into the blood.
Gas exchange can only happen in the alveoli (small air sacs of the lungs). The rest of the breath reaches these alveoli, where gas exchange takes place. Oxygen is transferred from the alveoli into the blood and Carbon di
oxide transferred from the blood back into the alveoli to be breathed back out.
By reducing the volume of air remaining in this dead space during each minute of ventilation (breathing), breathing efficiency and gas ex-changes improve.
In the following two examples, the volume of air drawn into the nose remains the same at six liters.
By reducing the respiratory rate from twelve breat
hs per minute, to six breaths per minute, the volume of air reaching the alveoli in the lungs increases, from 4.2 liters to 5.1 liters.
This represents a 20 percent increase in breathing efficiency.
RR * TV= MV
Nose: 12 breaths * 500ml = 6 liters (short shallower breath)
Alveoli: 12* (500-150) = 4.2 liters
RR * TV= MV
Nose: 6 breaths* 1000ml = 6 liters (longer slower breath)
Alveoli: 6 * (1000-150) = 5.1 liters
Slow breathing reduces the number of breaths per minute. This means more air reaches the small air sacs of the lungs, the alveoli, where gas exchange takes place.
By reducing the respiratory rate, proportionately more air per breath reaches the alveoli and less air remains in the dead space (Bilo et al., 2012).
It also requires significantly less effort by the body to perform 6 long slow breaths than 12 short fast breaths but that will be covered in a follow up article.
Exercises designed to permanently slow the rate of breathing can improve performance during strenuous exercise (Bernardi, Spadacini, Bellwan, Hajiric & Raskamm, 1998).