I can speak from experience of walks home from the Woodbine to Highgate with Ash, he does set a fair rate as well. Often needed a stop in a hostelry on the way back.
I do miss those days
I do a mix of high pace walk/jog then for the final 3 mins of say 10 I up the speed. then slow it down then repeat. those minutes go slow when you are really pushing. But I find on my 3rd burst of the higher speeds it seems to get a bit easier. until I reach the point I feel that it's time to stop as I am going to die.