Pace the marathon from constraints, not ambition
A marathon pacing plan should protect the opening, adapt to course and conditions, and preserve enough capacity for the final third. Start with a realistic finish-time range based on recent training and racing, then convert it into effort guardrails rather than a demand for identical kilometres.
Build a section card
Use course elevation, turns, congestion, aid stations, forecast, and exposure. Average goal pace is arithmetic, not a command for every split. A steep climb should not be repaid with an equally aggressive descent.
Use several signals
Compare pace with breathing, perceived effort, heart-rate context, fueling, pain, and normal coordination. One drifting number does not diagnose the cause. If several signals deteriorate, reduce demand before waiting for a dramatic failure.
Run the race-time predictor as a range, practise the plan in the tune-up race guide, and make intake executable with the marathon fueling planner.
Safety boundary
Stop and seek event medical support for chest pain, fainting, confusion, severe breathing difficulty, dangerous heat symptoms, or pain that changes normal movement. This pacing guide is educational and not medical advice or a finish-time guarantee.