I recently purchased my first Garmin watch (Forerunner 265), so I'm having to learn a lot of things about training for the first time. I am following a Garmin Coach plan to train for a 5k, and the plan has a mix of activities, including interval training. Where I live, it is often too cold during this time of year to train outside, so I'm having to figure out how to configure my training for an indoor track. This has sparked many questions.
1. I have used the Indoor Track Run to record base runs (constant pace) around 10:25/mi pace, but with varying degress of success. Often, the watch significantly underestimates my pace to be ~16:00/mi pace. For context, I only have access to a track which is 1/10 mi long. My understanding is that the watch should calibrate to an indoor track after running some number of laps, but is that calibration process assuming a standard 400m track?
2. I have used the Indoor Track Run to record an intervals run (variable pace) with a warmup and cooldown. Again, the watch is unable to accurately update my pace during these intervals. When I begin my fast-paced intervals, the watch continues to show paces around what I was running for the warmup. My suspicion is that this is a consequence of calibrating during the first couple of laps I run in my warmup. Is it possible to get accurate intervals pace tracking on indoor runs?
3. If the underlying problem is the track I'm running on, is it possible to do interval workouts on a treadmill with only the watch? From what I've seen online, my guess is no. Accuracy for runs on a treadmill seem to rely on calibrating to that specific treadmill after your first run by overriding the watch's recorded distance with that of the treadmill, but if running intervals, how is the watch able to distinguish between your "fast" periods and your "slow" periods?
As a result of recording inaccuracies, I'm getting very poor execution scores on my workouts. Beyond the incorrect stats being annoying, I'm also worried that my training plan will no longer adjust correctly to my fitness levels. If none of the above options are possible, what is the best way to continue following the training plan?