IF I INHALE PURE OXYGEN RIGHT BEFORE A RACE...WILL I RUN FASTER?

EPO doesn't increase oxygen uptake. Try again.

Jon Orange wrote:

EPO doesn't increase oxygen uptake. Try again.

Correct. It's the extra rbcs that do that BECAUSE of EPO.

You're gradually getting it. Painfully slowly though.

Well I didnt read those studies you mentioned. But usually the alveolar-capillary Hb saturation is 98%, Percentage saturation= Total O2 combined with Hb / Oxygen-carrying capacity of Hb) x100.

The PO2 in blood plasma in the lungs is 100 mmHg, at this point saturation of Hb is 98%. Oxygen loads from alveoli to into the blood and CO2 unloads and exicts the bload into alveoli. To which degree the saturation will decease depends of several factors, pH, temperature, metabolic demands etc (Bohr Effect), but Hb is assumed to be always fully saturated at alveolar-capillary level. During exercise it will decrease to about 35% and more, more Oxygen will be unloaded to active muscle tissues. Usually in rest we use about 25% of Oxygen we enhaled, the rest of it returns "unused" to the heart via venous blood. But during exercice more Oxygen is used because demands are higher. PO2 in tissues is 40mmHg, and when it decreses rapidly during strenous exercise and reach 10mmHg and lower the greatest quantities of Oxygen will be unloaded from Myoglobin (skeletal and cardiac muscle iron-protein compound). It facilitates oxygen transfer to mitochondria (where the magic happens i.e. they generate ATP). However Bohr Effect is not apllied on Myoglobin.

"During exercise, ventilation might increase from resting values of around 5–6 litre min−1 to >100 litre min−1. Ventilation increases linearly with increases in work rate at submaximal exercise intensities. Oxygen consumption also increases linearly with increasing work rate at submaximal intensities. In an average young male, resting oxygen consumption is about 250 ml min−1 and in an endurance athlete oxygen consumption during very high intensity exercise might reach 5000 ml min−1. The increase in pulmonary ventilation is attributable to a combination of increases in tidal volume and respiratory rate and closely matches the increase in oxygen uptake and carbon dioxide output. Breathing capacity, however, does not reach its maximum even during strenuous exercise and it is not responsible for the limitation in oxygen delivery to muscles seen during high intensity activity. Haemoglobin continues to be fully saturated with oxygen throughout exercise in people with normal respiratory function."

This one commes from this journal:

http://ceaccp.oxfordjournals.org/content/4/6/185.full

I do agree with someone who commented avobe that Oxygen used as a supplement could be useful when someone trains on a different altitude and not at the sea level. Because the partial pressure of the gases will be different in ambiental air above sea level.

I like this answer from my cousin Bojana B.

Try googling "is it harmful to breathe pure oxygen?". Be careful with your health and body.