How is this done? I always read guys saying they have a XX liter lung capacity. How does one figure this out?
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Testing lung capacity
- Thread starterFreeRestriction
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Thread Status: Hello
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Ya if theres a less accurate but suitable home version of the test that would be cool. Not sure if the balloon things serious or not.
Yes you can easily test the volume in water. Take a 10 liter plastic jerry can, drop 1 liter of water into it and mark the level with a waterproof marker. Continue in the same way until you fill it (creating so the scale). This step is not necessary if the can already has a reliable scale.
Then take it to the pool or a bathtub, submerge it and entirely fill with water, but keep it close to the surface (to avoid skewing the results too much with hydrostatic compression). Keep the opening down and blow as much air in a single exhale as you can. Use a snorkel or a pipe. Then close the opening, and measure the level of water remaining. Your vital lung capacity (VC) is the total volume of the can minus the water remaining. The total lung capacity (TLC) is equal to VC + RV (residual volume), but that is much more difficult to measure without using a trace inert gas. You can only estimate it.
Then take it to the pool or a bathtub, submerge it and entirely fill with water, but keep it close to the surface (to avoid skewing the results too much with hydrostatic compression). Keep the opening down and blow as much air in a single exhale as you can. Use a snorkel or a pipe. Then close the opening, and measure the level of water remaining. Your vital lung capacity (VC) is the total volume of the can minus the water remaining. The total lung capacity (TLC) is equal to VC + RV (residual volume), but that is much more difficult to measure without using a trace inert gas. You can only estimate it.
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One issue with exhaling into a balloon would be the change in air density from your lungs taking o2 and exhaling co2. Not sure how drastic the difference would be from a quick inhale exhale though.
I am not speaking about baloon (elastic), but about a can (rigid). With a balloon you'd need to calculate the compression due to the resistance of the balloon. CO2 takes the same volume as O2, and although the produced CO2 is not always exactly equal to the consumed O2, the difference will be totally negligible (likely below 1%). Addititonally there is no difference to the measurment with a spirometer.
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Ya i didnt even consider the pressure created from the balloon. So what would be a better container to use that could be measured. A trash bag perhaps? I suppose the biggest problem will be accurately measuring the inflated container if its an odd shape.
I repeat that I do not speak about any baloon, but about a rigid jerry can. As I wrote the ballon is not well suitable because of its elastic resistance. Besides it, it wouln't be easy to measure or calculate the volume of the ballon (or a trash bag). With the jerry can it is trivial - even a school kid can do it all in five minutes. If you calibratate the scale in the way I said (or use a jerry can with a scale), the measurement is pretty precise. Probably much more precise than a cheap spirometer.
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I have tried the balloon, water jug, spirometer, the pod and weights in a pool. The difference is less than my daily variations. The balloon is the easiest, weights in a pool is great on a warm summer day but a tethered line in 15 meters is more fun and lets you easily measure residual volume too. Not much better than the old one quarter of Vc estimate though. There is one thing about weights that took me a while to discover. Lead doesn't weigh what it says nor the same in water as it does out. 10% less is close.
Great. That is a simple, easy solution, that can be made even more simple
I just tried it right now, adjusting it to a normal sink filled with water. I took a 1 litre plastic measuring jug, and my snorkel, a then blew 1 litre out at a time through my snorkel, filling the jug with water again every time.
Can be done in 2 minutes...
What do you think of this test? My student Nic Mevoli used it.
There is a cruder test, much cheaper that any one can do and is spot on. You blow into a balloon, measure the diameter and calculate a formula. I got 5.74L no packing and 7.5 packing. Save the money here's the formula (circumfrence of balloon cubed)/ 3622= vital+25%=total.
There is a cruder test, much cheaper that any one can do and is spot on. You blow into a balloon, measure the diameter and calculate a formula. I got 5.74L no packing and 7.5 packing. Save the money here's the formula (circumfrence of balloon cubed)/ 3622= vital+25%=total.
Like stated by trux earlier the compression from the balloons elasticity skews the results plus getting an accurate measurement of an odd shape like a balloon isnt that easy.
Ok i just thought of a pretty cool way. Just take your camelback hydration bladder and blow into it and release the air and refill until your out of air. Only issue would be determinig the amount of air on the last fill.
Im able to fill up both my camelbak bladders in one breath for a pretty close total of around 5.3l give or take. I think there may be some pressure involved though toward the end of the fill but its atleast somewhat of an idea of your lung capacity.
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Well i tested using a 5 gallon bucket in the tub with accurate measurements on all measuring and im at 6.1 liters so the camelbaks are a bust.
Take a large bottle, 6 liters or so, put it in the pool and fill it with water. Invert it, keeping the open end submerged. Take a small hose and insert one end into the neck of the bottle. Take a full deep breath and exhale it into the other end of the tube, blowing the air into the bottle and fully exhaling. Once you have fully exhaled, remove the tube from the bottle, move the bottle vertically as necessary so that the level of the water in the bottle is even with the pool surface, cap the bottle, turn it rightside up and take it out of the pool. Now measure how much water it takes to fill the bottle up. That volume is your forced vital capacity (FVC). I use a 6 liter water bottle for this purpose.
If you can fill more than that with air, get a sponsor and let him pay for your pulmonary function test to measure all of this in a clinical setting, because you got pretty decent lung capacity.
If you can fill more than that with air, get a sponsor and let him pay for your pulmonary function test to measure all of this in a clinical setting, because you got pretty decent lung capacity.