Updated: Jun 9
Step 1. Get a Running Power Meter
My recommendation in order of preference.
(I have no affiliation with any company)
Step Two. Run with Your Power Meter.
Have power displayed on your main watch screen along with pace and heart rate to get an idea of how your power outputs relate to your pace and heart rate.
Try doing some runs where you only run to power, and ignore pace and heart rate.
Try my running power 3km-5km PB training plan for $19, available on trainingpeaks.
Step Three. Start Logging Your Data
The more data you have, the easier it is to analyse trends and build an appropriate training plan specific to your needs.
I recommend logging your data with dedicated software.