How to overcome the voice in your head that says you can't

Wise words from the legend himself! The little voice in my head was something I used to struggle with a lot when running; you know the one.. the voice that says "you've run far enough, you can take a rest now" before you're even halfway through your run (or maybe it's just me???). That voice used to sound so serious and authoritative, I had a tough time blocking it out. 

Eventually, I found a better way to deal with it.. Now, instead of that stern voice, my inner doubts may only be spoken by Micky Mouse, and only after he has been sucking the helium from balloons. The only problem I have now, is trying to not trip from laughing so hard at my inner doubts! it's got me some strange looks when I randomly burst out laughing while running, but I'm used to that already!