The secondary entrance of Avenue station is no doubt excellent for cardio, especially with the long flight of stairs. Just from going up and down the stairs frequently would truly be a workout in itself. Better yet, it's free as the stairs are outside of the fare-paid zone.
ETA: Corrected typo and the stairs are truly a workout
IIRC this is the deepest station on the Crosstown due to local grades.
Using TBMs instead of cut/cover needs deeper stations - in this case, it's even deeper than normal as Avenue Rd sits on the top of a hill. Sort of similar to how York Mills Station has long been unusually deep.