Sunday, August 2, 2009

. VOG2 man {maximal 02 consumption ability) The amount of 02 that can be actually consumed by a person, when h&she is working maximally haid.

Aha! the equpment is / is called VQo2 max In The above example if if is presumed that the athlete could not consume more than 4 litre ol 02/min. then his V002 max is 4 1/ mm. In (lie past. V002 max used to be expressed as I /min and m world athletes the V002 mot is around 41 rum N d days, the trend is to express V0o2 max in Terms of ml/'kg/ min. A worid o class sprinter is expected to haveV0O2 max around 75 ml/kg/min. The V002 max is the single best inde* ol Ihe person's capacity to maintain extremely heavy exacise The value ol V002 max. as common sense dictates is dependent on the efficiency of (i) circulatory. (ii) tespiratory and the [iii] muscular system. In short, where the ventilation volume and difusivity ot the lung are high the transport of 02 m trie blood is rapid. Hb% is saTisfactory. The delivery capacity for 02 at The tissue level is good, the V002 max is also high. Besides Ihe VOD2 max can be _i-..ilL impioved by susTamed tiainmg jsee also lung function TesTs. chap. 7. section IV), Oxygen debt Assume that a man is working extremely heavily and his 02 requirement is 101 min Assume further thai his VO 02 max wide supra) is 41 mm. It this man exercises for 1 minute then obviously there will be a defict ol 6 kteis (10-1) ol 02 Although he stops The exercise after 1 min he continues to hyperventilate during the recovery untrf he has consumed 5 Iiters of extra (extra = in addition to his resting requirement) O2 This 6 liters o* 02 is the "oxygen debt" (a term coined by A V Hill and his colleagues m the 1920s). Thus oxygen deW may be defined as the amount of excess oxygen that is consumed during recovery after an exercise. There are several causes as to why the 02 debt develops. Although Ihe details are debated a simple vision is as follows (i) at the onset of exeicise. the muscles get a ready supply ol 02 from its own myogtobin Dunng recovery the myoglobin is again reoxygenaled and the amount d 02 required for this purpose contnbules towards 02 debt. The total amount however is small not exceeding 200 ml. (ii) during the exercise, resynthesis ol high energy phosphate bonds like cr&ttme phosphate may be incomplete. Dunng recovery the CP rasynthesis occurs fully and the resynthesis inquires oxygen (iii) Lacte acid accumulates in seveier forms of exercise and its removel requires oxygen Quantitatively this is the most important cause ol 02 debt and this fraction of 02 debt is called lactic acid 02 debt: the rest is alactic acid 02 debt. Respiratory quotient (RO) Dunng a bout ol a severe exercise, the RO rises, from a normal value of about 0 a to values like 1.5 or more After the exerciser slopped the value of RO falls and may attain values around 0.6 or even less and then finalry becomes normal again. Explanation During exercise, when the respiration is stimulated, more C02 is blown out Than 02 consumed As the exercise pjogresses, lactic acid appears in the blood and breaks down the blood bicarbonate releasing C02. which in turn causes further hyperventilalion and further driving out of CO2. These are t he explanations of the rise of RQ. [Pacall RQ = volume of C02 exhaled volume of 02

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