Real simple - you must have had some outstanding girth exercise days. Now with that knowledge, why was your unit able to sustain the level of erection you needed, and why did those workouts feel so good? Now you need to try and duplicate those good workouts. If you try five days straight and you find you can't keep that up, try something different. This might take a few weeks, but have a plan and experiment. Also, it won't do you any good to shoot for five straight days, if every week something pops up to cause you to miss. Also, start dreading having to do it and soon you won't be doing it. You are much better off gaining a little less than optimum each week or month and sticking to a particular routine, then to gain a nice chunk one week or month, but at the cost of killing yourself to accomplish it.