jepuskar:
Is it safe to breath pure oxygen while running on a treadmill? For about 30 straight minutes...at an above moderate pace.
I ask because I know its not safe to overly exert yourself while diving and with a PO2 above 1.4/1.6...so....
I've done a google search but nothing conclusive so far.
Thanks,
J
Oxygen toxicity takes two forms: CNS oxygen toxicity, which is what is most dangerous underwater and is exasperated by activity, can cause you to seize, which can then cause you to drown. This is not a worry when you are in a dry environment, as the seizure itself is not necessarily dangerous.
Pulmonary or "whole body" oxygen toxicity, which is in part an inflammation of lung tissue, is more a condition of breathing high partial pressures of oxgyen for a long time. This can be a problem for patients breathing oxygen at the surface, but it is usually something that takes more than a day to develop.
Running while breathing O2 might accelerate the onset of pulmonary ox tox, but it is doubtful that you will have a CNS hit at a PO2 of less than 1.0 (you can't really get 100% because you rebreathe gasses in your anatomical and mechanical dead spaces).
More importantly, though, is why would you want to do this? This is not a new idea, and multiple studies show that this provides no benefit- here is one that was handy:
http://faculty.css.edu/tboone2/asep/JEParmstrong.html
Cardiovascular activity is limited by the ability of the body to *deliver* oxygen, not undersaturation at the blood/lung barrier. A rough analogy would be to think about a car with its tank 50% full versus 100% full. Extra weight aside, the car will perform exactly the same because it is utilizing the gas in the tank based upon size of fuel line and efficiency of the engine.
The best way to improve cardiovascular performance is to make sure you're getting the most out of your time on the treadmill. Chose a program that varies the speed and incline, taking you into periods of nearly uncomfortable effort, followed by periods of recovery that prepare you for the next interval of effort.
Cameron
