Is drafting worth it in a marathon?

Running in a group can save you around two minutes over 42 km – more into a headwind, almost nothing with the wind behind you. Here is when it pays, where to run, and how the wind changes everything.

The short version

Running alone costs you about 1–1½ minutes in a marathon compared with running in a normal race field.
Sitting right behind someone or inside a pack saves another ½–1 minute. Alone vs. in a pack: about 2 minutes.
The headwind is where it really counts. With the wind behind you, drafting gives almost nothing.
In a crosswind, move to the sheltered side – behind and slightly downwind of the runner in front, not straight behind.
Only draft at your own pace. A group that is 5 seconds per km too fast costs you more than any shelter gives back.

Why drafting works

Most of the energy you use when running goes into moving your body forward and up. But a part of it – a few per cent at marathon pace – goes into pushing the air out of the way. Behind another runner, the air is already moving with you, so you push less of it. The faster you run and the stronger the headwind, the bigger that air resistance is, and the more you save by tucking in.

Bar chart: what running alone, loose in the field, behind 1–2 runners or inside a pack is worth in a marathon — Faster runners gain more: air resistance grows quickly with speed. Alone vs. in a pack is about 2:08 at 4:00/km and 1:35 at 5:30/km.

When does it pay?

Situation	Is drafting worth it?
Headwind	Yes – the most. Into a 4 m/s headwind, a pack can save you several seconds per km.
Crosswind	Yes, if you move to the sheltered side (see below).
Calm	A little – about ½–1 minute over a marathon.
Tailwind	Hardly. The wind is already pushing you; run your own line.
Open stretches – bridges, seafronts, wide roads	Yes. This is where the wind reaches you. Between tall buildings it matters much less.
A group running too fast for you	No. Going over your pace costs far more than the shelter gives.

Where should you run?

Diagram: where to run in a headwind and in a crosswind — In a headwind, sit straight behind. In a crosswind, the sheltered spot moves to the side away from the wind – cyclists call it an echelon.

Inside the pack is best. In the middle of a group you are sheltered from the front and the sides. At the front you do the work; on the windward edge you get little.

About one metre behind the runner in front is close enough to feel the difference and far enough not to clip heels.

Follow the wind as the course turns. On a loop the wind comes from a new side after every bend – move to the sheltered side again.

Pick the right group early. Pacer groups (for example 3:30 or 4:00) are ideal: steady pace and plenty of shelter. Join one that runs your goal pace – not the one just ahead.

Watch out at the aid stations. Groups break up there. Take your drink, then move calmly back into shelter – don't sprint to catch up.

A coach's view

Two minutes is a lot – it can be the difference between a new PB and just missing it. But the biggest gain is not the shelter itself: it is that a good group helps you hold an even, calm pace for the first 30 km. Use the group to save energy, not to run faster than you planned. And when the group drifts away from your pace late in the race, let it go and run your own race.

See what the field and the wind are worth in your race
RaceDayCast shows the drafting effect kilometre by kilometre – alone, behind others or in a pack – with the race-day forecast.
Find your race →

Numbers from the RaceDayCast pace model (energy cost of running with air resistance and drafting, calibrated against published wind-tunnel and field studies). The values are averages for a typical runner; real groups are rarely ideal, so we use moderate shelter factors. Background: Pugh (1971, J Physiol) on air resistance and shelter in running, and Hoogkamer, Snyder & Arellano (2018, Sports Med) on cooperative drafting in the marathon.