I went through basic last year, 0240B was my serial and if anyone was on that please message me, anyway I dont remember hearing anyone say they actually did the run, everyone did the step test and if you struggle with the step test its time for some serious evaluation. You can expect to run 2k in your second week and build up to 10k by the end of basic, in farnham which is the field training part of the course, expect a 14k forced march, not running but walking with a ruck. Anyway, if you want to train for basic do STAIRS!!!! I was on the 7th floor, recruits are on floors 6-10 on the green side and 7-12 I think on the blue side, and you dont use the elevator, so forget running, go to a high rise and run the stairs. When you can do 15 floors and not have a prob, then do it with a 25kg pack, then you should be on your way to being almost prepared.
Chris