Originally Posted by
Kai Winters
We were encouraged to build our base with longer, slower rides. Today that is considered Zone 2 riding which builds the mitochondria as has been stated by others in this post.
Yes, Zone 2 has been touted by many as this powerful mitochondria builder, but the science doesn't seem to confirm it. Training
volume is reported to be the main influencer of mitochondria growth, with faster growth occurring up to about 90% of VO2max.
Increasing the amount of mitochondria is a good thing, but more important is how much oxygen the mitochondria can process. Studies suggest that higher intensity training develops mitochondria respiration (oxygen consumption) much more quickly than zone 2.