What's Brantley Gilbert afraid of?

Brantley Gilbert has been touring with Tim McGraw... and now he's having nightmares!  Brantley tells Country Weekly that he keeps "having the same nightmare where Tim knocks on the the door of my tour bus to go work out with him."  Brantley says he like to work out, do power lifting and other strength training, but Tim is on a different level.  Brantley admits his tourmate is more man than machine when it comes to working out.  Brantley says, "That man is like the Terminator.  I'm pretty sure he bleeds chrome."  We can all see that Tim is pretty fit.  Check out the photo from last fall's single "Truck Yeah".