Low lung capacity?!
Comments
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Probably easiest if I quote Dr Stephen McGregor:
Is ventilation volume a limiting factor to maximal endurance?
Sometimes you hear people say "I ran out of wind." Is that really possible? Can we reach a point in exercise when ventilation just can't keep up with demand? The answer is no, assuming you don't have acute asthma or some other severe pulmonary dysfunction.
We can measure a person's maximal voluntary ventilation (MVV), the maximal volume of air they can breath in and out while at rest, and compare it with their maximal ventilation during exercise. What we see is that untrained people only use about 60 to 85% of their maximum ventilatory capacity even at maximal exercise.
For example the MVV for an average male might be nearly 200 l/min. However, during a treadmill VO2 max test, they reach a peak ventilation of only 140 l/min. Highly trained athletes use more of their capacity, perhaps over 90%, but ventilation capacity is still not a limitation on performance. Unlike the story with cardiac output, even during maximal exercise, the ventilatory capacity is not maxed out.0 -
I would disagree slightly with what ddmrcp said about the time period. The spirometers I've seen will either run over a possible 6 or 12 second period, and I would say even a fit and healthy person is struggling to manage a maximal expiration for 6 seconds. If you can do anywhere near 12 seconds then you have some seriously restricted airways.
The percentage value is purely based on the ratio between your maximal expiration (FVC) and how much of this was expired in the first second (FEV1). You can look at interpretation of this to see how this compares to population statistics of people of the same age, height etc. to see how your values compare to the 'norm' (Hence the 130% figure mentioned would be in comparison to someone with the same characteristics. In terms of absolute values can't get above 100% obviously, and if it was near there you would probably have bad emphysema and your airways have fused) . As a general rule, the taller and wider the person, the larger their lungs.
In terms of how this may indicate any kind of athletic performance, it basically doesn't as we may have gathered. The lungs are remarkably efficient at taking the oxygen from the air and diffusing it into the haemoglobin we have (the total surface area for gas exchange is about 150 sqaure metres). You can fully saturate all the haemoglobin you have at maximum effort and you would still have spare capacity for oxygen transfer. This is why increasing the amount of haemoglobin will increase performance as there is still oxygen there to take on from the lungs.
It is interesting to note that some sucessful cyclists like some Armstrong and Indurain did have large lung volumes however.0 -
Alex & Tom, all very interesting. Glad to hear that my 5 seconds is not so abnormal!
Maybe it's a secondary association, e.g. large lungs = large internal chest volume in relation to weight, = potentially large heart muscle & stroke volume?It is interesting to note that some sucessful cyclists like some Armstrong and Indurain did have large lung volumes however.
It's also interesting that when you think about it, the only time you are really "gasping for breath" during exercise is when you stop or ease off after an intense anaerobic effort.0 -
Tom M wrote:I would disagree slightly with what ddmrcp said about the time period. The spirometers I've seen will either run over a possible 6 or 12 second period, and I would say even a fit and healthy person is struggling to manage a maximal expiration for 6 seconds. If you can do anywhere near 12 seconds then you have some seriously restricted airways.
The percentage value is purely based on the ratio between your maximal expiration (FVC) and how much of this was expired in the first second (FEV1). You can look at interpretation of this to see how this compares to population statistics of people of the same age, height etc. to see how your values compare to the 'norm' (Hence the 130% figure mentioned would be in comparison to someone with the same characteristics. In terms of absolute values can't get above 100% obviously, and if it was near there you would probably have bad emphysema and your airways have fused) . As a general rule, the taller and wider the person, the larger their lungs.
In terms of how this may indicate any kind of athletic performance, it basically doesn't as we may have gathered. The lungs are remarkably efficient at taking the oxygen from the air and diffusing it into the haemoglobin we have (the total surface area for gas exchange is about 150 sqaure metres). You can fully saturate all the haemoglobin you have at maximum effort and you would still have spare capacity for oxygen transfer. This is why increasing the amount of haemoglobin will increase performance as there is still oxygen there to take on from the lungs.
It is interesting to note that some sucessful cyclists like some Armstrong and Indurain did have large lung volumes however.
You're getting into the realms of something, even as a Sports Science student, which goes over my head: Is performance limited by the amount of oxygen you can deliver to the muscles/cells, or how much the muscles/cells can uptake. (From my limited reading, uptake)."A cyclist has nothing to lose but his chain"
PTP Runner Up 20150 -
My understanding purely from the above would be that performance is limited by the amount you can deliver to the muscles/cells, but that the "bottleneck" is not the lung capacity but rather the oxygen carrying capacity of the blood, i.e. the haemoglobin / red blood cell count.ShockedSoShocked wrote:You're getting into the realms of something, even as a Sports Science student, which goes over my head: Is performance limited by the amount of oxygen you can deliver to the muscles/cells, or how much the muscles/cells can uptake. (From my limited reading, uptake).
Maybe either haemoglobin levels or cell metabolic capacity can be limiting depending on fitness however, or on level of exertion?
Interesting now to think more about Armstrong's large lungs... Maybe lung capacity can become limiting (or more significant at least) if you have extremely high haemocrit levels, by whatever means...?0 -
It is generally accepted that VO2 max is limited by cardiorespiratory systems ability to transport O2 to the muscles.
http://physiotherapy.curtin.edu.au/reso ... vosmax.cfm0 -
Lighting this topic up again.
With regards to the comments suggesting that air intake is not a limiting factor, im curious as in my own circumstances when I am hill climbing I seem to hit the limit of how fast I can breathe before my legs start burning which in turn prevents me from increasing load and therefore meaning that my legs never reach that "burn" state..
I have had a spirometer test as part of an overall fitness test which suggested that my FVC was pretty normal, but my ratio of FEV1 to FVC was quite high 92%. The guy doing the test suggested that this could be the cause of my breathing limitations on a climb because when I exhale there is little residual air left in my lungs until I inhale again, wherease someone who has a lower FEV1/FVC ratio say 80% has air in their lungs for longer during each breathe cycle.
So would I be better actually breathing out intentionally slower?0 -
You'd be better off doing some specific cycle training to improve you threshold power and aerobic capabilities.carbonmanx wrote:So would I be better actually breathing out intentionally slower?0
