I'm assuming great focus, but if I used the term tunnel vision in relation to a "pre workout/workout" I'd be talking about the ability to block out all distractions at that moment in time and focus solely on the workout, which would be a great thing. Some pre workouts seem to do this much better than ohters. I for one, have many ADD-type qualities and at times I can lose focus when using some products that overstim me. Others, provide me with great energy and a sense of initense focus needed for amazing training sessions.