They will be just about into the "tapering back" period - the traditional method of preparing for the 26 miles is to build up to 22 miles or so, but in the last couple of weeks to take it easier so your muscles are ready but rested for the race.
I am not at that point, but am nearing the peak. And it is a sair fecht.
I am not a natural runner. Being of the chunky persuasion, even after having shed weight, readers won't see a human greyhound hurtling round the streets of Glasgow, it is more like Schnorbitz looking for a biscuit.
I do have a regular stride, but it is not pretty. You know how there is a bit of sniffiness about the distinction between a runner and a jogger? I am neither - meet The Ambler. But I don't care. However the course gets done, finishing is paramount.
Running is sore. After nine miles I begin to feel aches in various places. My right foot gets achy on the instep. My right hip has some odd thing in it that seems to pulse after a certain point. Knees are not great either, but a heavy wrap-strap on one or both, as required, cures that. My thigh muscles get stiff as if I am running through deepening mud. None of that gets better as the miles progress.
I can't run pain away, but just have to keep going. On the plus side though, my heart and lungs are superb. I breathe evenly and my recovery at the end of even the longest runs is quick. Decades of exercising and not smoking have been worthwhile.
The mind then has to compensate for the body.
As the miles progress, you count down - only eight miles to home, only six miles to home, only 45 more minutes running, only three more hills to do. And underneath all that, the reassurance that every step is a step nearer the end is crucial.
I've said before that I am doing this ultimately for me - to reclaim body shape and correct weight- but I am running for St Margaret's Hospice too, and don't want to underplay that.
What is touching is that over and above my supporters, people whom I would have regarded as only casual or professional friends, or even acquaintances, have been generous where they almost certainly have their own concerns and existing charitable loyalties.
Not only am I grateful to them, it is a driver for training - I could not bear to let these great folk down.
It is not even clear to me if I am responding to a stick or a carrot here, but whichever it is, this is ultimately the gain that overcomes the pain.
At the age of 54, I have continued to regard myself as a young man, and lifestyle and routine are not so different from when I was in say my 20s. Same wife, same job, same sports.
OK, I don't still have the Donny Osmond hairstyle, and I just can't stay up late partying without a severe penalty the next day, but vigour and health remain first class. It is the running over long distances that tells me the truth. Aches and pains carry on for hours after stopping, and the next couple of days I limp pathetically.
So it is not all cakes and ale. Indeed, it's neither at the moment. I am grinding out the last few weeks in mortification of the flesh.
Here's hoping I am up to the task. After 18 miles of painful ambling, it is in the balance.
l Remember my charity page at www.justgiving.com/Austin-Lafferty