we simply didn't care about every little detail. for example, if we had to run to a certain park to do intervals, we just run there. the time it took us to run from the school to the park was approximately 8 minutes. was it a mile? a little more? a little less? who honestly cares. when we ran intervals at the park, it was estimated as well. was it 800m? 874m? 946m? doesn't matter. after running intervals enough times, you get a feel for the distance and you just aim for consistent times.