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RunThreshold

Josh Kerr 4-Mile Tempo + Hard Mile

4 mi tempo, 3–4 min jog, 1 mi hard

Time
≈1h07
Hard
≈38:04
in zones 4–5
Difficulty
Very hardDifficulty 4 of 5 — Very hard
Inspired by
Josh Kerr

What we typed

Warm up 15 min easy. 4 mi tempo at threshold effort. 3 min 30 s easy jog. 1 mi hard at 5K effort or quicker. 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

5 steps

Warm up

easy

15 minZ2

Run

tempo at threshold effort

6.4 kmZ4

Jog

3m 30sZ1

Rep

hard at 5K effort or quicker

1.6 kmZ4

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
5K effort or faster

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 miles tempo, 3 minutes' jog, then 1 km hard.

Build the scaled version in Forge

About this session

The story

Coach Danny Mackey described a cut-down run for Josh Kerr: 4 miles at tempo, then 1 mile hard — sometimes progressed to 5 miles of tempo plus the hard mile.

What it trains

Threshold strength, then a faster mile on tired legs — the finish of a 5K in miniature.

Who it's for

5K–10K runners and milers with a solid threshold base.

Sources 1
  1. How Josh Kerr Trained His Body and Mind to Win an Unexpected Olympic Bronze — 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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