No, there's no need for that, as race day will be my 5th time running this exact same course, I'm pretty familiar with the course. Also, during marathon training, I don't usually run a full marathon. I run something close, say 38km or so, and leave the actual 42.2km for race day. And I don't usually run too much 1 or 2 weeks before race day to save my legs. Last week's 36km was and will be my longest run during this whole training period. I've already started to taper, as I only ran 25km this Sunday.