Statistics for ONE exercise, or for training as a whole. The user's goals, injuries, per-muscle weekly sets and recent working weights for a review of their training are in get_coaching_context (task='weekly_review').

The parameter is named kind, not stat_type/stat/type/metric. It defaults to 'volume', the only value that needs no exercise_id.

exercise_id is REQUIRED for kind='progression' and kind='prs' (they are per-exercise) and is ignored for kind='volume' (whole-training-volume over time). Progression or prs without an exercise_id is an error, not a whole-library default; exercise ids come from list_exercises.

'progression' → per-date top set, est-1RM (Epley), volume + PRs; 'prs' → personal records; 'volume' → total training volume over time with trend %. One movement the user logged under several catalogue rows is read as one history; same_movement_ids then lists those rows. get_coaching_context bundles these numbers with the user's goal and context for planning.