Spin class is a cardiovascular workout, and you will get out of it what you put into it. So if you put in the effort needed for the various types of workouts, you will train those "portions" of your cardiovascular fitness.

That being said, many spin classes tend to be high intensity, so you must ensure you are balancing things out. Typically, an athlete will only do 1-2 higher intensity workouts a week, the remainder are moderate or lower intensity.

My clients who like spin classes, will do the spin class, but won't necessarily follow the high HR guidelines set by the instructor...ie they will do the same movements but lower intensity to match their needs.

that is the beauty of the spin program, you can work at your own pace!