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RunVO2max

Deek's Quarters

8 × 400 m at 3K–5K effort, 200 m fast float

Time
≈50 min
Hard
≈13:51
in zones 4–5
Difficulty
Very hardDifficulty 4 of 5 — Very hard
Inspired by
Rob de Castella

What we typed

Warm up 15 min easy. 8 × (400 m at 3K–5K effort, 200 m float at a steady controlled pace, not a jog). Cool down 12 min easy.

Fit File Forge built the steps below from these words — the same steps your watch gets.

Describe your own

The session

4 steps

Warm up

easy

15 minZ2
8×400 m

Rep

3K–5K effort

400 mZ4

Float

At a steady controlled pace, not a jog

200 mZ1

Cool down

easy

12 minZ1

Targets

Set by race effort. Your paces follow from your threshold pace — about what you could race for an hour.

3K–5K effort

Save it and race efforts become your own paces, from your profile or your Garmin training. Without them every rep keeps its effort cue.

Scaled version

Jog the 200 m recoveries, or take the 400s at 10K effort.

Build the scaled version in Forge

About this session

The story

Made popular by former marathon world-record holder Rob de Castella ('Deek'): eight 400 m repeats, each followed by a brisk 200 m float rather than a rest.

What it trains

VO2max and the ability to recover while still moving quickly — the heart rate never really drops.

Who it's for

5K to marathon runners who can already handle standard 400 m reps with jog recoveries.

Sources 1
  1. Deek's Quarters Workout Will Whip You Into Speed-Shape Fast — Outside Run, 2021

I've been using the AI Training Coach from day 1 for marathon prep and have found it to be a huge step up from ChatGPT/Gemini — I couldn't be happier.

Dave F.Marathon athlete

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