The fastest way to understand Workout Writer is to write one simple session and watch the preview take shape.
Paste this into the editor:
Warmup 10 min Easy
4 x 3 min Threshold, 2 min Easy
Cooldown 10 min Easy
As you type, the preview updates straight away so you can see what the app thinks you mean and what will be sent to your watch.
4 x to 6 xThreshold with Tempo1km)If the preview looks right, you're already most of the way there.