I didn't do bjj for a few months but stayed active and continued working out, lifting weights and cycling mainly. I did a class on Thursday and got smoked by 2 advanced people. Even though I did poorly I still felt such a high afterwards. I kept thinking about the class yesterday and did aznother one today which went a bit better. What is it about combat sports, specifically grappling that causes this rush afterwards? It's much different than the post workout endorphin rush from running, cycling, or lifting. I feel excited hours after the class now and eager to go again. Why is the grappling post workout high different than other workouts?