What do football coaches mean when they tell you to be a loose running back and howdo i become one?

Question

I played running back one day and the coaches told me to become a loose running back what does that mean? and how do i become loose

Answer 1

I will agree with the one above me Tahoe, but ask the coach. I am a coach and what I say can be totally different then the next coach. Like when tackling I use the term "bite the ball" others use wrap up means the same but said differnt  

Answer 2

They probably mean that you would run better if you weren't so tight. Keep practicing, and talk to your coaches. Stretch those muscles out.