Warm up for Zone 2 rides/runs

I have noticed that in sessions where we are prescribed intervals, it is much easier to keep a high pace(run) or (power) after the intervals while yet staying in zone 2 heart rate.
In most cases the pace/power I can sustain is much higher than what I was capable of during the warm up. I think this also shows as a negative aerobic decoupling in some cases.
I am attributing this to the intervals firing up the right muscle patterns. Is this correct?

Does anyone else experience the same?

With the above in mind the question that arises is how to get to this state during prescribed Z2 workouts. I have heard Dr Inigo San Milan state that it takes up to 20min to clear lactate after intervals. This could hinder the objective of the Z2 workout, so I am curious on the views of others on this topic.

What is the best way to warm up for these Z2 sessions and what do you do?

Thanks in advance.