The Importance of “Zone 2” Cardio
Rusty Moore wrote an article on the importance of “Zone 2” cardio.
In it, he summarized a 2-hour long interview of a world-renowned cardio expert: Dr. Iñigo San Millán.
In this essay, I will summarize Rusty’s summary.
Before we get to the cardio recommendation, we must first understand the role of mitochondria.
Mitochondria are organelles that are responsible for oxidizing fat.
Some people have stronger mitochondria than others. Elite endurance athletes are known for having very high mitochondrial density.
Mitochondrial strength declines with age, which is why the older you get, the harder it is to stay lean. People with weaker mitochondria are also more susceptible to type 2 diabetes because of their inability to burn body fat.
So far, this sounds like bad news for anyone who isn’t an elite endurance athlete.
The good news is there is another way to improve your mitochondrial strength.
There are six cardiovascular training zones: 1 to 6.
You can think of Zone 1 as a slow walk and Zone 6 as an all-out sprint that you…
