Skip to content
FIT FILE FORGE
Get started

RunVO2max

Zátopek 40 × 400

40 × 400 m at 5K–10K effort, 200 m jog

Elite session. As written this is for very experienced, high-volume athletes. Most people should start with the scaled version under the steps.
Time
≈2h20
Hard
≈1:09:16
in zones 4–5
Difficulty
EliteDifficulty 5 of 5 — Elite
Elite · scaled option below
Inspired by
Emil Zátopek

What we typed

Warm up 15 min easy. 40 × (400 m at 5K to 10K effort, 200 m easy jog). Cool down 10 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
40×400 m

Rep

5K to 10K effort

400 mZ4

Jog

200 mZ1

Cool down

Easy

10 minZ1

Targets

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

5K–10K 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

2 × 10 × 400 m with 200 m jog, 5 minutes between sets.

Build the scaled version in Forge

About this session

The story

Emil Zátopek, introduced to interval training in the Czech Army, often completed as many as 100 × 400 m in a day. Forty is a big session inspired by that approach.

What it trains

Aerobic power through sheer repetition — lots of running at 5K–10K effort in digestible pieces.

Who it's for

Very experienced, high-mileage runners. Everyone else: the scaled version.

Sources 1
  1. Marking the centenary of the birth of Zatopek — World Athletics, 2022

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

Related workouts

NOT HERE? DESCRIBE IT.

Describe it and it's built for your Garmin — your coach can plan the weeks around it.

Open ForgePlan a block with your coach

Garmin and Garmin Connect are trademarks of Garmin Ltd. or its subsidiaries. Zwift is a trademark of Zwift, Inc.; Fit File Forge isn't affiliated with Zwift. Athletes and coaches named here don't endorse Fit File Forge.