Supposing a "runner" who has done one 3/4 mile run (that ended with eating a burrito) has a 4 mile race coming up in 4 days .... anyone have any advice on how to make the most of such a small amount of time?
Pick up your race packet, then stand by the finish and watch the runners come across. There is nothing one can do in 4 days to improve the situation. You could walk/run the course. If you are otherwise in great condition from other activities, you probably could complete the race running at a moderate pace.