1.2 m. And then you just adjust the pace to where you get the trot you wants. 😊
I usually go about 4 feet apart for trotting piles.
For my 170 cm tall warm blood I use one big step, should be around 1 Meter for a collected, shorter trot and around 1,20 meter for a more extended trot.
A good base distance for trot poles is 1 meter = approximately one big step. And then you just adjust a bit depending on the length of the horses stride. I would say that three big steps is more the distance between canter poles, that would make it approximately 3 meters and again with adjustments for the horses stride
I make mine 2 big steps apart but I ride a thoroughbred with a short step. Mine are about 5 feet apart.