Does it defeat the purpose of a rest day to do cardio on it? Because I am currently cutting and on my rest days i have been doing about 30 mins of cardio and some stretching. Is that okay? Or would it be better to not go to the gym at all on my rest days? By the way my current routine is:

Day1: Legs/Core
Day2: Upper Push
Day3: Upper Pull
Day4: Rest (which has been cardio and stretching lately)
repeat.

Thanks! All responses are appreciated.