Name: Efficiency Factor Data Field
Author: 0094994

Efficiency Factor (EF) Field surfaces your EF (power divided by heart rate) live during a run, instead of only after the fact from a Garmin Connect export.

A rising or falling EF trend is one of the earliest readable signals of fatigue or overreaching.

This field smooths it with a rolling average, colour-codes it against your own personal band (green in band, amber as an early warning near the edge, red once you're sustained below it), and gives a single vibration alert if you stay below band for longer than you've set, so you don't have to keep checking the screen.

Features:

• Rolling-average smoothing with a configurable window (default 30s)

• Fully user-configurable band edges — set your own low/high EF thresholds

• One-shot vibration alert on sustained fatigue, with a configurable trigger time

• Handles sensor dropouts gracefully, holds the last valid reading rather than flashing zero

• Exports the smoothed EF to your FIT file for post-run analysis

Built for ultra and endurance runners who want an early, glanceable fatigue signal on-wrist, not just in the post-run report.

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New device support policy: New Garmin device releases are assessed for compatibility within 1 month of launch, with support added as soon as the SDK allows.