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RunThreshold

2 × 20 min Threshold

2 × 20 min at threshold, 2–4 min easy

Time
1h11
Hard
40:00
in zones 4–5
Difficulty
HardDifficulty 3 of 5 — Hard

What we typed

Warm up 15 min easy. 2 × (20 min at threshold effort, 3 min 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
2×20 min

Rep

threshold effort

20 minZ4

Jog

3 minZ1

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.

Threshold 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 × 12 minutes, or 3 × 10 minutes with 2 minutes' jog.

Build the scaled version in Forge

About this session

What it trains

Forty minutes at threshold — a big aerobic stimulus for half-marathon and marathon runners.

Who it's for

Half-marathoners and marathoners, and 10K runners with a solid base.

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.

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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.