sSre. But it wasnt my plan, just stupidity ;) I started at the front, and even faster than 4 mile pace, more like 3k pace or something! First km in 3:35, second in 3;43, and from there on it was hanging on for life basically.
The difference in those two paces are only about 4 seconds per 400m. Your plan may just as easily have you running 4 seconds fast per 400 the first half the race and 5 seconds or more slow the second half the race