Hi, I'm on my second week of the "Improve Your Fitness" Level 2 - HR Based training plan.
So far, all of the workouts have specified the HR Zone that I should aim for at each workout. But I've seen a few future workouts that not only specify the HR Zone but also the "effort". Some of them even have different "effort levels" while having the same HR Zones: "Run, threshold effort, Z4, 7 minutes. Run at 10K effort, Z4, 3 minutes."
What does treshold and 10k "effort" mean? Is it a kind of Sub-Zone? Is it something purely subjective or does the Garmin watch have any measurement to gauge this "effort"?
Thank you!