Substack: Progression: A powerful training heuristic Progression: A powerful training heuristic by Joel FilliolStrategies for creating space to hit the optimal training doses in both the short and long term. Read on Substack Newer:Substack: Zone 1 is where the magic happensOlder:Substack: Don't be a January champion PostedJanuary 29, 2026 AuthorJoel Filliol