So I am about to get a little technical here, but we are all adults so I think it is safe. The item for today is VO₂ Max and this can be defined as follows:

VO₂ max is properly defined by the Fick Equation:

VO₂max = Q(CaO₂ ? CvO₂)

where Q is the cardiac output of the heart, CaO₂ is the arterial oxygen content, and CvO₂ is the venous oxygen content.

In English this means in sports where endurance is an important component in performance, such as long distance running, world class athletes typically have high VO₂ maximums. World class male athletes, cyclists and cross-country skiers typically exceed 80 ml/kg/min and a rare few may exceed 90 ml/kg/min for men and 70 ml/kg/min for women.

What my VO₂ max is a mystery to me as I have never been tested, this what the testing looks like this:
I am working to increase it through specific training runs. The ideal is to run intervals of 1200 meters at a 5K pace with 2 minute “jogs” in between to cool down. Well I ran 5 intervals of 1200m at a 7:00/mile pace after warming up with a 2 mile run and then another 2 miles to cool off. It was a great workout and felt great right after, what I did not count on was the next day.

Today I ran a nice, easy 10 mile run and my legs felt like they weighed 100 pounds each. I hope the intensity training is worth it because stairs are now my greatest enemy and cement blocks on my feet would be a relief.