New York City Marathon

The day, before the day

49°F air, 37°F dew point, five bridges.

Those are the climate normals for New York in early November — what to expect, not a forecast. Meridian swaps in the real one once the race is close enough for a forecast to exist. Everything below is computed by the same engine that runs on the home page.

This profile is a shape, not a survey. It is built from publicly stated facts about the course — the Verrazzano in the first mile, the Queensboro at fifteen, the Fifth Avenue rise from twenty-two, and the 250 m of total climbing the race publishes. The whole shape is then scaled so its total ascent lands on that figure, which makes the climbs the right size relative to each other even though the ground between them is a sketch. It is here so the architecture exists. A real segment-by-segment profile comes from a GPX file, and when one arrives it replaces this without anything else on the page changing.

Mile by mile

The pace the course supports, not the pace you wrote down.

A flat mile in these conditions is worth 6:56 for this runner. Every row below is that pace re-priced for the ground under it. The right-hand column is what the terrain is charging you, in seconds.

Mile	What happens	Pace	vs flat
1	Verrazzano descent	8:41	+105s
2		5:34	-82s
3		7:03	+7s
4		6:47	-9s
5		7:01	+5s
6		7:03	+7s
7		6:48	-7s
8		7:07	+11s
9		6:47	-9s
10		7:03	+7s
11		6:50	-5s
12		7:07	+11s
13	Pulaski Bridge	7:03	+7s
14		6:38	-18s
15	Queensboro Bridge	7:49	+53s
16	First Avenue opens	6:03	-53s
17		7:05	+9s
18		6:52	-4s
19	Willis Avenue Bridge	7:10	+15s
20		6:43	-13s
21	Madison Avenue Bridge	7:16	+20s
22	Fifth Avenue begins	6:45	-11s
23		7:14	+18s
24		7:14	+18s
25	Into Central Park	6:47	-9s
26	The last rise	6:56	—
26.2	Finish	6:57	+2s

Fuelling

Three moments, and a sentence for each.

Not milligrams. Nobody has ever stood in a start pen and converted their body mass into a sodium target. The engine works in rates internally and then rounds hard, because your sweat rate could be four times another runner’s and Meridian has not measured it.

Before

A proper carbohydrate meal two to three hours before — around 110 g, low in fat and fibre so it clears. Porridge, a bagel with jam, rice.

During

Take 7 gels, roughly every 25 minutes — first one around 25 minutes in.
Around 350–500 ml of fluid an hour is about right.

After

Eat within the hour or so: a real meal with carbohydrate and around 20 g of protein. Nothing special required — this is lunch, not a supplement.
Keep drinking across the afternoon rather than all at once, and salt your food — you lost more sodium than you think.

This is the plan for a three-hour runner on a normal November day. In the app it moves with the forecast: hotter and the fluid goes up and the carbohydrate comes down, because heat slows your stomach down at exactly the moment you are asking more of it.

What this is actually saying

Bank nothing on the bridge. Spend it on First Avenue.

The Verrazzano in the first mile is the most expensive ground on the course and it arrives when you feel best, which is why so many people ruin their race in the first ten minutes. The model says give the mile away.

The Queensboro at fifteen is the second bill, and it is the one that matters, because it lands at the point in a marathon where a runner has least left to give. What follows it — the long drop onto First Avenue with the crowd noise — is the cheapest ground of the day and the easiest place in the world to spend more than you have.

Fifth Avenue from twenty-two is where the race is decided. It is not steep. It is just long, and it is late, and by then every second you overspent earlier is being collected.

What this page is not

Not a plan. A translation.