The hardest part of running, goes the advice of tough coaches, is putting on your damn shoes and getting out of the damn door. Hell yeah, you’re meant to reply. Just do it! And I know from experience that advice is right most of the damn time. I have hovered around in kitchens, adjusting my laces, pulling jackets on and off, while I find 101 reasons not to take to the streets, only to discover, once I am out, that I am happy as I can be.

To the addicted obsessive, however, the hardest part of running can be taking your damn shoes off. I’m writing this late on a Tuesday night. I ran four miles today, eight yesterday, and plan to get up early and do five tomorrow including my first session of hill sprints since I came back from injury six weeks-ago — 200-metre bursts of speed up a hill that are meant to build your quads, and generally butch you up.

I should call it off. My legs hurt and my hip flexors are strangely stiff. As I wrecked my hips last year, taking a break would be the sensible thing to do. I should let my body calm down and go out again when I feel fresh. It’s not as if I need to run. My next big race is a half-marathon in May. My 12-week training programme doesn’t even begin for another fortnight. I could take a day off, and it wouldn’t matter in the slightest. And yet I have the fixed idea that I must be covering 30 miles a week before the training even starts so that I can do a 12-week “advanced” half- marathon programme for real runners rather than the “intermediate” programme for dilettantes and wimps. No rational argument can talk me out of it. A part of me knows that my position is ridiculous. If I run tomorrow, I could injure myself again or spoil myself for the weekend when I have a couple of decent runs planned.

What is the point of a man my age trying to run a half marathon in 1:39:59 rather than 1:45:00? I ought to have learned from my injuries that the most miserable feeling I can have is the depression that comes from not being able to run at all.

If I stay at home, though, I will think I have failed, and the failure will nag at me all day. I will want to make up the lost miles the next time I am out, and in all probability pay for that.

In short, I have a compulsive running disorder. Pleasure plays its part, as it does in any addiction. The feeling moving as fast and as freely as water down a hill brings. The satisfaction of overcoming early stiffness and settling into a rhythm you could keep going for hours. These are real joys that are accompanied, if you are lucky, by a “runner’s high”: a euphoria that wipes away anxiety as your body produces illegal drugs — endorphins (heroin, essentially) and endocannabinoids (self-explanatory) to dull the pain and keep you going.

To the addicted obsessive, however, the hardest part of running can be taking your damn shoes off

The dangers come from running when running brings only pain; from running when a part of your mind knows the effort is self-destructive. In these moments the tyranny of unrealistic expectations takes charge. You have a 12- or 16-week training programme you’ve taken from the web and your addicted mind knows only one thing: you must stick to it whatever the perils. I have heard a therapist argue that runners can easily come to resemble women with eating disorders. In both cases, sufferers measure themselves against wholly unreasonable models: the starvation chic of the fashion industry; the insistence that you must improve your finishing time with every race.

In both cases, sufferers compare themselves to others and find themselves wanting. The Strava app is the runners’ equivalent of Vogue. You log on and see the runners you follow going further and faster every day. Your running defines your worth and self-esteem, and if you allow any one attribute to define you — your thinness, your pay cheque, your attractiveness to others, how fit you are, the number of likes you get on social media, your title at work — your pursuit of unattainable goals will one day go too far and lead you down the road to madness.

Update: It’s Wednesday morning. I woke up and the pain in my hips had gone. Hell, I thought, let’s put on the damn shoes and get out of the damn door. I ran the five miles the schedule dictated. I even did the sprints up a hill. I feel fine. More than fine, actually. I feel confident and self-satisfied. A small part of my befuddled brain knows one day I will pay for that.