[Scott Johnston]

Sorry for the slow reply to your very good questions.

Do the AnT on the terrain that simulates your goal event.  For most mountain runners we have used 15% to 30% depending on the athlete level and having access to an incline trainer.  For mixing terrain you may need to do both the AeT and AnT tests on flattish and steep grades.   Some people will find these thresholds to be the same for steep and flat. But, others will see a big difference depending on grade.

We suggest the steeper incline for the AnT test because it simulates the terrain and grades where most mountain runners are hitting their limit.

Scott