Existe-t-il un tutoriel en français?

Non, mais essayez la traduction automatique:

QuickGuide Introduction courte.
Utilisez TrailRunner avec Nike+iPod.
Utilisez TrailRunner avec ForeRunner.

> TrailRunner Help Book
> Tutoriel en anglais

Mise à jour: Jean-Daniel a écrit un cours d'instruction au sujet d'utiliser TrailRunner avec un ForeRunner:
> Garmin : les suites d'une intégration Mac OS

What's the difference between activities, workouts, routes, tracks and way-points?

Problem: You have used other applications that import tracks and these never use vocabulary like activity, route or workout. Why is TrailRunner not using the same terms? And by the way, what is the difference between a track, an activity, a route and a workout?
Background: TrailRunner is more or less two applications in one: on the one hand a route planning application managing a personal network of tracks and on the other hand a journal for your sport activities. For your better understanding, please take a look at the TrailRunner QuickGuide. The differences should be obvious after you have read it. If not, please be so kind to let me know what you do not understand so I can improve either the QuickGuide or even TrailRunner.

> QuickGuide Tutorial