Lots of people will be running the London marathon on 26 April this year, some of them GPs.
This is my first ever marathon, the first half century of my life having passed comfortably watching the event, like sensible people.
When I announced my plan to run in the marathon, most people said: 'What on earth were you thinking?'
A marathon is a serious undertaking for anyone, especially someone who hasn't run one before. It's in a good cause, though - I'm running for Cancer Research UK and I'm looking for donations.
In return for - hopefully - a fiver of your surgery profits, I would like to offer you my seven-point training plan, so that you too can spend your days exhausted and your nights aching. This involves:
1. Leg strengthening programme with personal trainer and former regimental sergeant major, Hannah. This includes a punishing regime of horrible squats, horrible lunges, horrible press-ups and horrible stuff that involves a horrible, huge inflatable ball.
2. Eating porridge. I'm worried this may result in me growing a beard and a kilt and putting a poster of Alex Salmond on the fridge. London is big on porridge these days - everywhere sells it, with fruit, honey, chia seeds, alfalfa. I have mine with salt in a bothy, the way the real men do.
3. Lots of running. Endless running. Running is good for you, but also deeply boring.
I've been experimenting with listening to audiobooks of my own novels while I carry out my endless running routine, in order to actually sleep through most of this.
4. Multiple trials of specialist marathon nourishment. Currently, I am testing jelly babies, jelly bears, jelly snakes, jelly dinosaurs, even jelly gels.
Also engaged in existentialist debate with family as to why we ever thought teaching children to eat babies was OK.
5. Industrial-design sports underwear offering maximal trussage. You have to think about this stuff.
6. Maintaining positive mental attitude by not reducing consumption of alcohol, coffee or chocolate until absolutely necessary (at the start line, probably).
7. Developing stiff upper lip attitude by listening to Ed Miliband saying he will have 8,000 more GPs by 2020 and not shouting: 'Where are they coming from? Does he know how long it takes to train one?'
I aim to raise £5,000 for Cancer Research UK. You can donate at www.justgiving.com/Lowths/Please do it now. Or you'll forget ...