Training load

Cairn computes the classic training-load model from your full activity history:

• CTL (Chronic Training Load) — your fitness, a long exponentially-weighted average of daily load.
• ATL (Acute Training Load) — your fatigue, a short average.
• TSB (Training Stress Balance = CTL − ATL) — your form.

These are charted under Analysis. The chart series colors are fixed and independent of the brand accent, so fitness/fatigue/form always read the same.

Load is recomputed as a follow-up on every import, so adding or correcting a source updates your curves.