INCREASE YOUR CAPACITY TO KNOW AND LEARN
Physiological capacities tend to be the result of multiplying a physiological volume and a physiological rate/pace/frequency. The maximal capacity of a physiological system is important as it directly determines the maximal extent of physiological work that can be achieved, and can indirectly determine many more aspects of physiological function.
For example, Cardiac Output (CO, L/min) is defined as the volume of blood pumped out of the left ventricle of the heart in one minute (60 seconds). It is the result of multiplying Stroke Volume (SV, mL) and Heart Rate (HR, bpm). Stroke Volume is defined as the volume of blood pumped out of the left ventricle of the heart per one contraction of the heart (one beat), while Heart Rate is defined as the number of heart contractions (beats) per minute. Stroke Volume determines the amount of blood pumped out and Heart Rate determines how many times will the heart pump out blood during the next minute to pass.
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Since Red Blood Cells (RBCs) carry within them Hemoglobin, and Hemoglobin carries Oxygen (O2) and/or Carbon Di Oxide (CO2), Cardiac Output directly determines the delivery extent of blood and nutrients to the cells. in order to extract Oxygen and nutrients into the cells, they must first be delivered nearby the cells. Thus, Cardiac Output indirectly determines the potential for extraction by the cells.
The cell cannot use (utilize) Oxygen and nutrients that have not been extracted, and cannot extract anything that was not delivered (offered to the cells). Thus, Cardiac Output indirectly and partially determines the ability to utilize Oxygen and nutrients within the cells. Cells often dispose of substances into the blood stream (blood tissue). Since blood carries these substances away, Cardiac Output directly determines the disposal capacity via blood specifically.
As indicated in other posts, chemical buffering occurs either within the cell (prior to disposal) or within blood tissue. The ability to buffer within blood tissue is partially and directly determined by Cardiac Output since the more blood pumped per minute, the more buffering opportunities are offered by sheer volume alone.
Minute Ventilation (VE, L/min) is defined as the volume of air exchanged in and out (inhaling + exhaling) of the lungs in one minute (60 seconds). It is the result of multiplying Tidal Volume (VT, mL or L) and Respiratory Rate (RR, bpm). Tidal Volume is defined as the volume of air exchanges in and out of lungs per one breath, while Respiratory Rate is defined as the number of breaths per minute. Tidal Volume determines the amount of air exchanged in and out and Respiratory Rate determines how many times will the lungs be inflated and deflated with and of air in the next minute to pass.
Air is a mixture of gases, water vapor, and particles that we breath into the body via the Mouth or Nose. Commonly, air is made up of 79% Nitrogen (N), 20.93% Oxygen (O2), 0.03% Carbon Di Oxide (CO2), and the rest consists of water vapor, and other possible particles such as dust. Changes to the content of air occur according to changing circumstances and environmental conditions.
Since Minute Ventilation directly determines the maximal volume of air exchanged per minute, it also directly determines the volume of Oxygen delivered to the lungs, and directly determines the potential for gas exchange between the lungs and blood stream. Oxygen that does not reach the lungs, cannot be extracted from the lungs into the blood stream, thus limiting the gas exchange process and extent.
Gas exchange between the lungs and blood stream include the extraction of Oxygen from the lungs into the blood stream, and the extraction of Carbon Di Oxide from the blood stream into the lungs (O2 and CO2 move in opposite directions). Once CO2 has been extracted into the lungs, it is disposed of by means of breathing it out. This volume of CO2 includes any volume of CO2 that was not previously used in other chemical reactions prior to reaching the lungs. Accordingly, Minute Ventilation directly determines the overall ability of dispose of CO2 that has reached the lungs to the environment (outside of the body).
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Furthermore, Oxygen that has not reached the blood, cannot be offered to the cells, not extracted into the cells, nor used within the cells, thus meaning that Minute Ventilation indirectly determines the potential for aerobic energy production, and by that, the potential for aerobic fitness as well.
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