Let me give you an example.
The other day I was doing a tempo run. For those that don't know, that is running at about your threshold pace, which is based on the body's ability to take in oxygen. I wasn't going quite that fast, but it was quick enough I'd have to make a point of pretending I could casually hold my end of a conversation while running.
So, fairly difficult. How did I make it easy that day?
I made it my own special game. I thought, it would be great if I had company on a workout like this. Voila, an imaginary runner providing support and a sense of 'we're in this together' was now running alongside me. Then I thought, I miss the days I was running in a pack doing runs like these. Voila, a second runner on my left and a third right behind me.
Now they were all running with me and it was the power of four pushing each other while remaining relaxed for each other. Great! I was now running with ease.
Uh oh, its getting hard again. A couple miles have gone by and I could feel my face tensing a little, my shoulders going up slightly, my upper body wanting to twist awkwardly forward and to the right.
Mental playground, where are you? My pack isn't enough anymore!
Time to grant them superpowers.
My pack can now be handed any of my mental or physical tension. They can hold it for me, and I can let it go without a further thought.
Honk honk! "Nice pace! Lookin' good!", a man in a car yelled as he drove by.
I smiled. Thanks to my mental playground.