Heart Rate Derived Metrics (HRDM) – Knowledgebase

Definition

Heart Rate Derived Metrics (HRDM) allows Xert to estimate key training metrics for activities that don’t include power data.

It’s especially useful for:

Rides on a bike without a power meter (commuter or gravel/MTB)
Travel/rentals
Running or cross-training sessions (when no power is available)

The feature requires HR data, so use a heart rate monitor, and ideally a cadence sensor for cycling.

What It Means

When HRDM is enabled, Xert uses your heart rate (and cadence, if available) to estimate how hard the activity was and how it likely affected your fitness and fatigue.

HRDM can estimate Xert's metrics including XSS, XEP, Difficulty Score, & more.

How HRDM Works

HRDM first analyzes your historical data to learn your personal relationship between:

Power
Heart rate
Cadence, when available

Once that relationship is established, Xert can estimate training metrics for any activity that includes:

Heart rate, or
Heart rate + cadence (more accurate)

Important: HRDM is only applied when an activity has no power data. If power data is present - even if incomplete - Xert will use the power data for that activity.

How to Enable HRDM

Go to:

Profile Settings > General Tab > Heart Rate Derived Metrics (HRDM)

You can also improve accuracy by entering your known resting HR and max HR instead of auto-estimating from your activity data.

Running + Garmin Running Power

If your Garmin watch records Running Power, Xert will treat the activity as having power data and may not use HRDM.

If you want Xert to estimate training strain from Power Data for runs, you can sync the run to a dedicated Running sport profile and track your running signature & training loads separately.
If you simply wish to account for the runs as part of your cycling cross-training, you should disable Running Power for the Run sport profile on your Garmin device. Then Xert can estimate XSS for the run using heart rate via HRDM.

Where You’ll See It

On the Activity Dashboard, with a Heartrate Derived Tag
In the Activities Table, with the HRDM tag

Common Misunderstandings

HRDM is not used if power data exists in the activity.
HR-only estimates are useful, but HR + cadence improves accuracy for cycling.
Accurate HRDM depends on having good historical power + HR data to learn your unique patterns.

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