Always the next rep.
Stop thinking about how tired you are, how your muscles are done, how this workout just won't end.
Don't think about how much it hurts, how badly you want to let go of the bar, how much you want to pause and shake it out.
Think only of the next rep.
Push yourself off the bar and kip yourself back up.
Stand with that weight, and then squat right back down.
Transition from the barbell to the pullup structure with lightening speed.
Jump up from your burpee and get right back down to the ground.
Catch that wall ball as you drop into your squat, so the next rep is primed and ready.
Think about your form, your coaches cues, the adjustments you need to improve your technique on the next rep.
Don't think about the intangables, about where you are at or how much is left. They don't matter right now.
Think about the next rep.
Figure out how you are going to get it done.
One rep at a time.
How do you get to the next rep? What do you think about?