Decode Running Pace and Training Zone Data

Your running plan keeps telling you to run in zone two or hit a certain pace and you are not sure what either means in practice. This explains how your zones were worked out and how trustworthy that is, what each zone does to your body, and how to actually apply them on a run. Good for runners following a structured plan who want it to make sense.

<context>
You have started following a structured running plan that uses pace zones or heart rate zones and are unsure how to interpret the numbers or apply them in practice.
</context>

<task>
**Translate the training zone data into practical guidance:**
1. How your zones were calculated: the test or estimate used to set your zones and how accurate it is likely to be
2. What each zone means physically: what is happening in your body at each intensity, in plain language
3. How to run in each zone: the specific feel, effort level, and pace you should be experiencing in easy, moderate, and hard zones
4. Why most runners run their easy runs too fast: the most common mistake and what to do about it
5. How to use this data to structure a training week: a simple principle for balancing intensity across sessions
</task>

<output_format>
- Plain-language explanations of each zone
- A zone reference table: zone name, effort description, how it should feel
- One priority for the next four weeks
</output_format>