I am starting to use Intervals.icu for creating pace-based running workouts to use on the treadmill. These workouts use a percentage of the threshold pace. Is there some guidance on what the best way of setting the Threshold Pace?
Can I use the Critical Speed from the Pace page (assuming I trust the three runs that are highlighted)?
Yes, you can use critical speed, as long as you trust those highlighted runs.
To start, you could use anything, and then refine it as time goes. For example “best guess for the pace I can sustain for about 1h” would work to start, then you can refine your methods over time.
Another option could be using a recent 10k pace as your threshold.