Hello,

Is it possible for my arms to shrink after cardio?

I have my football training 30 minutes after workout. I feel like my arms shrink after that.

I wonder if it's just optical illusion

Unless you have stopped resistance training altogether for a matter of months and decreased your caloric intake drastically, no, it's not likely that they have shrunk. A possibility is that you may see them as 'flat', which can occur when you're depleted of glycogen.

Alrite, thanks for the info.