If you’re running, then I’d include the warmup and cooldown as part of the run. If you’re talking about dynamic stretches before or after running, then no.
Before all runs, I do about 5min of band work for hip and glute activation before I walk out the door. Then I do about 100m worth of drills and dynamic stretching before I start my run.
On workout days, the warmup is the first 3km followed by 3 strides, then start the workouts.
The medium run becomes the workout. Warmup, do the work out, then cool down. E.g., 3km warmup, 5x1km w/2min rest, 3km cool down. In my case, it’s not 80min, but the work is what’s important. If it’s a tempo workout, you might start w/5km but when that becomes 10km or longer the total time for the workout will also get longer.
Yes. This is basically Barry P (3-2-1). The long run being 1x120min. Even if it takes you longer than 120min to run 21km, it’s enough.
The key point here is that you need to build up to a sufficient amount of time and/or volume before doing workouts. When the workouts start, volume might go down a bit before going back up. Most plans will recommend you already have a base of X km or miles per week. The plans will then progress you to higher mileage by the end.