Type of exercise leading to Texan leaving out of exacerbation (7)

I believe the answer is:

aerobic

I'm a little stuck... Click here to teach me more about this clue!

'type of exercise' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

(Other definitions for aerobic that I've seen before include "Requiring free oxygen to breath" , "(Of exercise) improving intake of oxygen" , "Of a process depending on oxygen" , "Requiring free oxygen for respiration" , "(Of exercise) increasing oxygen in blood" .)

I've seen this clue in The Irish Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.