We had a cross country route that left the school, went around a wood, crossed a ridge about half a mile from the school where we were visible to the games teacher, ran around another wood and then back to school.
We used to go into the first wood and have a smoke until an adequate amount of time for running the mile or so around the first wood had passed, appear on the ridge running like we meant it, into the second wood, had a smoke, waited for another similar period and puffed back into school suitably breathless.