The amount of air we breathe depends on how active we are and therefore how much oxygen our bodies need. Normal relaxed adults breathe in and out between ten and fourteen times a minute. Breathing like this they take in between 5 and 6.8 litres of air. Pump up the action and the lungs really start pumping too. Hard physical exercise soon gets us panting for air and our intake leaps to ninety litres of air every minute, with barely a second or two for each breath.
Spread this air intake out over the average lifetime and you will see that we need a fantastic amount of air. In fact it is estimated that each of us will breath 367,900 cubic metres of air. If you have ever seen pictures of the giant airships that flew fifty or sixty years ago, this amount of air would fill two and a half of the biggest of them!
Picture Credit : Google
