Respuesta Ventilatoria Al Ejercicio

The purpose of this experiment was to measure frequency of breathing (f), tidal volume (TV), and pulmonary ventilation (VE) during an incremental (progressive) test and a submaximal constant-load test, and to determine the different factors controlling these ventilatory responses during exercise. The expectations for the experiment were to observe increases in TV, f and VE during both tests.The respiratory system plays a major role in maintaining blood gas homeostasis. Its mayor function is to supply oxygen during metabolism, eliminate carbon dioxide produce and metabolism, and regulate hydrogen ions concentration to maintain acid-base balance during rest and exercise. The respiratory system must provide a mean for the replace O2 and remove CO2 from the blood. The body compensatesthis gas exchange as a result of pulmonary ventilation and diffusion. The term pulmonary ventilation is defined as the movement of air in and out of the lung. One minute ventilation is the product of the frequency of breathing (f) and the amount of gas moved during either the inspiration and expiration phase of each breathing cycle (Powers & Howley, 2007)

In the other hand, diffusion is movementof molecules from an area of higher concentration to an area of lower concentration. The concentration of oxygen in the lung is greater than the concentration of oxygen in the blood, therefore oxygen move from the lung to the blood. Similarity, carbon dioxide concentration in the blood is greater than the concentration in the lung, hence carbon dioxide move from the blood into the lung to beexpired. These gas exchange mechanism between the lung and the blood is almost in complete equilibrium and represents the highly organization of normal lung function.

During exercise, the rate of oxygen and carbon dioxide consumption increase, increasing the concentration of blood gases. Also, the concentration of lactic acid and hydrogen ions increases affecting acid-base balance. Therefore,pulmonary ventilation needs to be increases in other to maintain arterial PO2, PCO2, and pH within the narrow limits of homeostatic conditions (King, 2007). The increase in pulmonary ventilation increases the amount of oxygen delivered to the alveoli and the removal of carbon dioxide form the blood.


EQUIPMENT

Monark cycle ergometer
Breathing valve
Expired air tube
Nose clip
MouthpieceHeadpiece
Heart rate belt
Computer-based Metabolic System
Metronome
RPE Chart (Rating of Perceive Exertion Chart)

PROCEDURES

To set the equipment and prepare the Subject

1. The mouthpiece was attached to the breathing valve, which had an exhalation side and a inhalation side.
2. One side of the expired air tube was attached to the exhalation side of the valve.
3. The other side of theexpired air tube went to the computer-based metabolic measurement system.
4. The subject placed the mouthpiece his/her mouth, and an assistant placed the headpiece on subject’s head to support the mouthpiece.
5. The subject placed the nose clip on his/her nose and a heart rate belt under the chest.
To measure f, TV, and VE using a Progressive Bicycle Ergometer Test.
1. Three assistant wereselected to keep track of the time, change the work load, obtain the subject’s RPE (Rating of Perceive Exertion), and count the respiratory frequency.
2. After the equipment was set and the subject was ready, the subject sat quietly on the bicycle ergometer.
3. Resting pulmonary ventilation was measured for 1 minute.
4. At the end of the resting period, the subject began to pedal at 50 rpm at a loadof 0.5 for one minute.
5. The load was increased 0.5 each minute until volitional exhaustion.
6. The computer-based metabolic system measured the values for VE (ATPS), VE (BTPS), VO2, TV, and HR.
7. The respiratory frequency (f) was manually counted. The assistant watched the subject breathe through the breathing valve, counting the number of time the expiratory flap inside moved.
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