# Metabolism

## Metabolism Chart

<figure><img src="https://2352761052-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FjRC3E2CZmJKDmDzgyBKM%2Fuploads%2FAR3nb49krpNHftX36dV7%2Fimage.png?alt=media&#x26;token=876b2c0d-b217-42c8-836f-d9308e00474b" alt=""><figcaption></figcaption></figure>

The metabolism chart estimates your reliance on fat and carbohydrates for energy, depending on exercise intensity.

{% hint style="info" %}
Humand use different energy sources depending on exercise intensity. At low intensity, fat is primarily utilized, while at higher intensity, carbohydrates become the main source.
{% endhint %}

* FATMAX: This is the point where fat oxidation (utilization) is most efficient. By maintaining power within the yellow zone (FATMAX), you can train effectively to reach your goals.
* Duration: The estimated time that you can sustain the power at the FATMAX point.
* TSS (Training Stress Score): The estimated training stress score achievable if power is maintained at the FATMAX level for the specified duration.