I have tried doing a number of practice runs for the 1.5 mile x2, I don't understand why I can do it on land yet on a treadmill I can't complete the last run, I have my PJFT in 4 weeks can anybody help please.
There are many environmental differences between running outside and on the treadmill, and one rarely gives a true indication of you performance on the other. (Think temperature, wind, gradient, humidity, motivation. Not to mention the psychological differences of running along a road or staring at a wall/bird in the mirror.)
There's an element of playing the game here: if you know your test will be on a treadmill then train, or at least finish your training package, on a treadmill. the converse is true for tests run around the AstroTurf.
Running with a weighted pack may help as second best, but ensure you seek advice from a PTI or Trainer as to the weight and distance to cover initially.
Remember not to get too anxious before the test as this will hamper your performance. Relax, focus and throw one foot in front of the other!