Defines the route: geometry, elevation, surfaces, and segments that will be used for the simulation.
Source & Trim: Load from .gpx / .fit / .csv, then (optionally) Trim to the connected race portion.
Segmentation: Split the route into analysis units.
Automatic: Coarse / Medium / Fine.
Manual: Split / Merge / Move end of segment via Custom segments.
Re-applying Automatic segmentation can overwrite manual edits.
Surface: Per-segment Smooth / Normal / Rough to inform rolling resistance.
Name: Give individual segments a recognisable name.
Use collection courses as bases you plan to reuse.
Inside an optimization, you can safely tweak (trim, segmentation, surfaces) without cluttering your collection.
If a tweak should be reusable, promote it back as a new course with the option "Save as course".
Grouping is defined inside optimizations to collapse many segments into a few execution groups (e.g., Climb, Flat with headwind).
Groups don’t modify the course; they tell the optimizer how many power targets to use.
Name courses clearly: Event – Year – Discipline (e.g., “IM 70.3 Switzerland 2025 – Bike”).
Start with Medium segmentation; refine only where terrain/wind meaningfully changes.
Keep surfaces honest — Crr assumptions depend on them.
Forgetting that re-applying Automatic segmentation after manual edits can wipe those edits.
Over-segmenting early, then fighting a noisy pacing table later.