And it wasn’t as if he had never made an effort. I made so much effort, he thought to himself, as the train rocked back into motion. I tried so hard, did what you’re meant to do. He meant it about weight loss, but perhaps he meant it about everything.

It had taken James a lot of nerve to go to the fitness class. He’d nearly changed his mind and gone home a couple of times. Once when the chirpy gay guy on the reception desk looked at him humorously and said, ‘Here for weight loss?’ And then in the changing rooms, with all the other men whose air of shame, of having turned themselves in for some deserved punishment, made him feel even worse that he himself was here. All that stopped him from turning straight around and going home was that he’d promised Karl he would give it a try. Karl had been the one who’d sent him the link. GAIN CONFIDENCE THROUGH EXERCISE, it said, with a series of images of fat and fattish people, like James, exerting themselves with what seemed like unforced glee. It was rare to see bodies like his own in promotional material. The email had taken him aback because James and Karl had never discussed James’s weight before, as they had never discussed many things before – but as with many of those subjects, it didn’t mean that Karl had not given them any consideration.

‘I just thought you might give it a try, fam,’ said Karl, ‘because the thing is, as I see it, you don’t like being the size you are, but you’re never going to do anything about it because so many people are utter dicks about bigger guys exercising, but this is designed to get round that very problem. So in short, yeah. Also, it’s only a taster course, and if you do the first one I’ll take you for a curry after. Which will hopefully really piss off the guys who run the course.’ James blinked. It was very difficult to argue with any of this, but as he glanced around at his fellow inmates, he wished that he had, and that he hadn’t put the weight on in the first place, and that he was anywhere else: really anywhere.

The man taking the course hadn’t seemed a good choice at first, either. He was lean, sporty; had various numbers tattooed on his forearms, like a prisoner. He wore a black athletic singlet that said FINISHER, and underneath gave details of some preposterous race that he’d taken part in: 12 hours, 52 miles, 2,500-m elevation. Yet this frightening specimen turned out to be called Giles and the numbers on his arms were, it transpired, his kids’ birthdays. ‘By the end of these three sessions,’ said Giles, ‘I’ll have won you over to the idea you can feel confident exercising. Or your money back.’