Mentally rehearsing tough spots in workouts or competitions can be a useful tool to beat those obstacles when you meet them in real life. Here’s a formula to help you build an effective script for visualizing success.
Source: Use Visualization to Power Through Tough Workouts
I’ve used visualization differently to get myself through a workout. I used it to distract myself, think about something else entirely. There’s some times I can’t remember how I’d progressed to that point (IE on a run), but I felt fine.
My Warfarin Diet 