Berlin K on K-off Challenge

Aug 13, 2025

Ready to start training?

If you already having the Pacing app, click try to import this workout:

Don’t have the app? Copy the reference above,
to import the workout after you install it.

A breakdown of “Berlin Marathon - Ep. 1: Survive the Session” from The Welsh Runner. Here are the essentials. Watch the full video for nuance.

12 x K on K-off: 12 reps of a K-length interval at threshold or marathon-pace push, paired with an easy jog recovery (the “off”).
Pacing: his K segments ran around 5:30 min/mi (roughly his marathon pace), with offs just under 6:00 min/mi. Around 16.5 mi over 95 min (around 5:47 min/mi overall).
Fuelling: a gel every 20 minutes (around 40 g each) supplies around 100 g carbs per hour, plus 200 mg caffeine split between the start and the one-hour mark. Use watch alerts for timing.
Heat and fatigue: train in warm, humid weather to match Berlin. Tolerate heavy legs and keep effort controlled.
Mental tricks: watch alerts as small mental breaks, anchor on the upcoming interval, and use each K as race practice.

Warm-up: 5 km easy jog.
Repeat 12 times:
- K: 0.8 mi at around 5:30 min/mi (threshold/marathon effort). Scale to your marathon pace if slower.
- Off: 0.4 mi easy jog at around 6:00 min/mi or slower. Pure recovery.
Cool-down: 2 km easy jog.
Fuel: gel (around 40 g carbs) every 20 min (around 5-6 K reps), water or electrolytes as needed. A caffeine tablet (around 100 mg) if your stomach handles it.
Total: 16-17 mi, 1.5-2 h depending on speed.

Try the 12 x K on K-off session, set the K pace to your marathon target, and use the Pacing app for nutrition reminders.

References