Mileage is still increasing in the weekly long run for the next few cycles, before the trimming back in the last couple of weeks.
I did a 16-miler on Monday.
Although I have not run a marathon for more than 25 years, my body is now remembering the effects of long-distance running.
Knees and ankles ache in the later miles, stomach becomes empty in a thoroughly unpleasant way, leg muscles become heavy and sluggish - all transmitting negative impulses to the brain which interprets them and converts them into a desire to stop and rest.
And yet, the moment you actually do finish the intended route and stop running as planned, within minutes you have a completely opposite feeling.
It has been worth the pain and misery, and you are already working out how much you have moved towards your goal and improved stamina.
I am not a natural runner.
My legs are not long but are heavily muscled, and my upper body is broad - though less so now that I have lost so much weight. But I can only look on with envy at the greyhound-esque men and women who whip by me on the pavement of an evening.
To use a different animal metaphor, they are Red Rum, I am the 'orse from Steptoe and Son. I have also again remembered the faffing about. Marathon training is a lot of fuss.
I have bought proper running gear - leggings and a light zip top, a little grab water bottle, and new running shoes - which I was fitted fpr professionally in one of Glasgow's specialist running shops, in a bizarre episode that involved them filming the back of my feet as I ran on their treadmill in full pinstriped suit and tie.
Before going out on a training night, I carefully dress, including putting a small towel round my neck inside my top, filling the bottle with a mixture of fresh orange and carbonated water, and getting Radio 4 on my little radio.
I plug in my earphones, put on my baseball cap, and get going. And that's me for up to three hours, grinding it out.
The most difficult logistical part of the business is finding a route to run.
I live on the South Side of Glasgow, on the edge of the hilly districts of Newton Mearns, Giffnock, Clarkston and Kings Park.
I have done a lot of running around those. In a bus or car, or even walking, a hill is hardly noticeable, but if you are running up it, it can be sore. Downhill is frankly not much better.
So as my mileage has increased, I have had to plot routes that are as flat as possible, with a diminishing range of roads that lack rises and falls.
One new source of assistance since I did my previous marathons in the 80s is the internet.
There are websites for runners and walkers that allow you to open up a map of your chosen area, and plot out a route along the roads shown.
I have become addicted to this, and the wife always seems to know when I am looking at running maps online, "You're doing it again aren't you? " she says in a world-weary tone.
I think it is the way I grin to myself when I find runnable sections of road that both gives me away, and gets her goat.
Safety is an issue - last week I was crossing Barrhead Road when a car speeded up as it headed towards me and some nutter pumped his horn at me for no doubt daring to obstruct his mastery of the road.
So as you can see, there is a lot of organization that goes into what is at first glance the most natural of activities.
We were given two legs to run with over the plains of Africa millions of years ago. But thank heavens for decent running shoes and a radio.
n Remember my charity page for the hospice movement www.justgiving.com/AustinLafferty