Cycling is a typical low-intensity aerobic exercise.
Runners like those who run half/full/815 marathons ride bicycles for recovery purposes.
With bicycle exercises using a low gear chainring below mid-compact, it is difficult to expect an effect of level 2 or higher.
Matching a 1:1 gear ratio is the same as saying that you are not doing high-intensity exercise.
You need to use a chainring of at least 56t for it to be considered exercise, and professional athletes use 60t or more.
