The marathon
Note
This page is a synthesis; the individual claims are graded on the pages they link to. The marathon’s energy demand and the role of fuel are well established and elite training for it is well described, but the precise training balance is coaching practice rather than trial-tested.
In the marathon, fuelling decides the result as much as fitness does. Energetically it is almost entirely aerobic, in the region of 97 to 99% (Spencer & Gastin 2001; Baker et al. 2010), so the engine that matters is the same as the half marathon’s, only held for two to five hours or more. Elites race it just under the lactate threshold, while most runners cover it at a comfortably sub-threshold intensity, the further below the longer they take (distance-specific training). What changes at every level is that no runner stores enough carbohydrate to cover the distance at race pace, so the result turns as much on managing fuel as on fitness.
What decides it
The aerobic qualities still set the baseline: a high lactate threshold, good running economy and the VO₂max ceiling beneath which both sit. On top of them, two endurance-specific qualities decide the marathon. Durability, the resistance of threshold and economy to the wear of three or four hours, is what separates a held pace from a collapse. And glycogen availability is the binding constraint: run low on carbohydrate and the body must lean on fat oxidation, which supplies energy more slowly, forcing the abrupt slowdown known as hitting the wall. Holding pace late, when tired and part-fuelled, is the event-specific skill.
Training approach
The base is the highest of any of these events: a very large volume of easy aerobic running (Haugen et al. 2022), distributed pyramidally with the hard work a tapering minority on top (Casado et al. 2022). The signature sessions are the long run, extended and often carrying a block at marathon pace, and sustained threshold work to lift the ceiling the goal pace sits under. VO₂max intervals keep a modest place to preserve the ceiling and economy. The whole programme funnels toward marathon pace as the race nears, the distance-specific logic at its endurance extreme, and it sits closest to the Canova method of building comfort at race effort.
A marathon block that trains only fitness is incomplete. The fuelling plan is part of the preparation: rehearsing race-pace fuelling on long runs, and training the gut to tolerate high carbohydrate intake so it can be used on the day.
Racing it
Start at or just below goal pace and aim for even or slightly negative splits. The classic error is banking time early; it is almost always withdrawn with interest after 30 km, because the early overshoot burns a larger fraction of carbohydrate and brings the wall forward (Grivas 2025). Elite marathoners vary their speed by only about 3% across the whole race (Hanley 2016). Fuel is non-negotiable: carbohydrate loading in the days before, a tested pre-race meal, and a rehearsed schedule of in-race carbohydrate throughout, at intakes the gut has been trained to absorb. See race pacing.