All of this is short term speculation, but I must admit that after class last Tuesday I didn’t feel sore. I did not feel sore the next day as well.
Usually when I go to grappling class I become stiff that night and the next day. I work out a few more times in the week doing things such as lifting weights, jogging, performing calisthenics and playing basketball or tennis but it never helps with soreness.
It seems simple, but I believe the fact that I am not sore may have something to do with the fact that I have been doing Jiu-Jitsu and grappling exercises daily that work out muscles specifically related to the art.