This may not be the same, but being athletic and exercising most of my life, I realized early on the importance of breathing. Controlled, relaxed, and yet focused breathing. Super important in my opinion.
Something else I learned and I'm sure this is not related but could be considered mindfulness is when I have been hungover badly or in minor withdrawals, I knew the thoughts that went through my head were false. It was the alcohol talking, doesn't always make it easier, but I am completely aware that any bad thoughts or panicky thoughts were a lie, they were heightened by the alcohol. 2 cents, that all.