jobo
Grandmaster
well no you really don't, black belt level at some clubs requires you to be an elite athlete, with elite athlete levels of fitness.No, but you need to be healthy to make black belt.
If I were to have all of the knowledge of everything needed to pass the black belt test suddenly downloaded into my head right now, I could not physically complete the test at my current state of physical fitness.
Completing the gold belt test was a task for me. This is letting me know that I need to supplement my martial arts training by hitting the gym.
clubs thats that hand belts out three times a year, require no more than base level fitness to reach black belt, any other requrement would cut off there money supply, as they would run out of punters very quickly.
will you get fitter doing karate( at most clubs), yes if the level of fitness you started with is abisminaly low. which to be fair sounds like you
no, if you started of with average to good fitness in the first place, you may even regress as it not challenging enough