The Mona Fartlek structure with four opening 90-second fast and float repetitions instead of two. The structure is the useful part: effort can change with terrain, weather and the point of the training week without changing the identity of the session.

Canonical sequence. A multiplier applies to the complete group immediately before it.

Exact workout

(90 s fast + 90 s controlled active recovery) × 4 → (60/60) × 4 → (30/30) × 4 → (15/15) × 4

Fast sections are strong and repeatable. Floats are controlled active recovery. Use contrast by feel. The added 90-second repetitions increase load without changing the character of the workout.

Use heart rate only as overall session context.

Build it in Garmin Connect

Build four repeat groups: 90 s fast + 90 s recovery ×4; 60/60 ×4; 30/30 ×4; 15/15 ×4. Leave targets open.

Start it on the watch

Sync the workout to the watch. Open the Run activity, then Training or Workouts, select the workout and choose Do Workout. Menu wording varies by model.

Optional warm-up: 2 km at conversational effort. Optional cool-down: 1–1.5 km at conversational effort. Adjust or stop when pain changes movement, conditions become unsafe or the planned effort is clearly wrong for the day. Completing the saved file is never more important than preserving the purpose of the week.