How does one start to look and feel that way?
They do the things required.
"I am this, I am that."
Look - all these visualization shenanigans, with your green tea and chakra beads are great and all...
Heck, I read mine every morning with at least 45 minutes of meditation.
But let's not forget that saying "I am fit" and visualizing yourself running up the hill...
Only means something if you make the difficult and conscious choice to run up the damn hill.