I've done it here in 2 easy events. No need for variables in the end, it relies on the bar width only. Have a look. I've kept your old logic in there but disabled.
https://dl.dropboxusercontent.com/u/495 ... dited.capx
You MAY need to relate it to a global variable in future, it's easy to adjust, or you could still rely on the width of the bar if you wish i.e. if width=1 then show character's tired animation, reduce speed etc something like that.