The ABC's and Running

Starting this Monday (and every Monday) The ABC's and running. A series of noteworthy topics about running. As the weeks flow in alphabetical order, suggestions for topics would be appreciated.
Just send me an email.
Today's topic: AIR

Air is a mix of 21% oxygen, 78% nitrogen,
and approximately 1% other gases.

All around us -> Air. We inhale and exhale the invisible, usually unconscious of its existence. Without air we would not be running.
Our body's ability to take oxygen out of the air we breathe and utilize it for energy is remarkable. The process starts in the lungs where millions of tiny sacs called alveoli exchange oxygen for carbon dioxide. (We are aerobic organisms.) The hemoglobin in our bloodstream picks up the oxygen and delivers it to the cells for energy.
The human body cannot store oxygen so luckily we live in a huge ocean of air.
For the freshest air, plan your next run in a forest
where trees (by Photosynthesis) can remove CO2 and release O2! Now that's a good thing.

I love the smell of air after a hard rain ~

"Both unfit and fit people breathe about the same amount of air in and out during heavy exercise." - Runner's World Trivia