Signature Extraction – Knowledgebase

Signature Extraction is Xert’s process for updating your Fitness Signature after each activity by analyzing your power data and recalculating your Maximum Power Available (MPA). It ensures your fitness model accurately reflects real-world performance, automatically adjusting if breakthroughs or near-breakthroughs occur, and is visible in various Xert reports and charts.

Summary Generated by AI

Definition

Signature Extraction is the process Xert uses to determine your updated Fitness Signature after an activity.

Each time you upload or sync a ride, Xert analyzes your power data and recalculates your Maximum Power Available (MPA) to determine whether your current Fitness Signature accurately reflects your performance.

What It Means

Your Fitness Signature (TP, HIE, and PP) defines how your MPA behaves during a ride.

Signature Extraction checks:

Did your effort confirm your current signature?
Did you exceed your limits (a Breakthrough)?
Did your performance suggest a small adjustment?

In simple terms, Signature Extraction keeps your fitness model aligned with your real-world performance.

How It Works

When an activity is synced:

MPA is calculated second-by-second using your current Fitness Signature.
Xert checks whether your power exceeded your predicted limits.
If a Breakthrough occurs, your Fitness Signature is updated.
- Bronze → One parameter improved
- Silver → Two parameters improved
- Gold → All three parameters improved
If you came very close (a Near-Breakthrough), your signature may be slightly adjusted.
- Empty Medal → Very close to MPA; may confirm or slightly reduce signature.
If no maximal effort occurred, your signature remains unchanged.

A minimum amount of time near MPA (currently ~5 seconds) is usually required for a new signature to be extracted.

Important Note: If your Fitness Signature changes after extraction, Xert automatically recalculates key metrics for that activity - including XSS (Low, High, Peak), Focus Duration, Specificity Rating, and MPA - so your data reflects the updated performance model. As a result, real-time data field values may appear slightly different after the update.

Where You’ll See It

On the Xert Performance Management Chart (XPMC) as Breakthrough circles
On the Activity Details page
In Breakthrough Reports

Important Notes

Signature Extraction typically happens automatically - no action is required.
Sub-maximal rides do not trigger a new signature.
You can manually adjust, & re-extract a signature if needed.

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