This is great! I remember when I was first getting into running back in like... 2010 / 2011... I started to realized how much my mood / headspace would affect my performance:

• If I started out in a poor mood, usually, I wouldn't run as well;
  • I now try to use time out running as something to bolster my mood and hit a bit of a 'reset' button.
• If I was dreading the exercise, as soon as I got within 2~3k of the end of my run, my legs would just die. "Close enough", my brain would think, and just stop telling my legs to move;
  • Now I approach it as, "2~3k left! I can do anything for 10~15 minutes!", and find another gear at the end;

I'll admit to putting a bit more emphasis on visualization and positive thinking when I go climbing as compared to my running, which I take pretty casually these days. But it certainly goes a long way. If I start a climbing route thinking, "There's no way I can do this... it's way too hard/scary/runout!" there's a HUGE chance that the entire episode will be a struggle, and my brain wont recruit even close to the power that's required (or available).

The mental game is real.

Great post!