Equal-duration fast and controlled active-recovery float blocks that descend from 90 seconds to 15 seconds. 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) × 2 → (60/60) × 4 → (30/30) × 4 → (15/15) × 4

Fast sections are fast but smooth. Floats are controlled active recovery, not tempo and not complete rest. Run by contrast and feel rather than a narrow pace target.

Heart rate is secondary because the changes are too short for precise control.

Build it in Garmin Connect

Build four repeat groups: 90 s fast + 90 s recovery ×2; 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.