Nonchalantly I swap legs, clasp my hands, and stretch my arms out in front of me. I can see my reflection on the other side of the room — and though I say it myself, I look pretty bloody cool.

    “Do you exercise regularly?” asks Tony.Advertisement

    “Not in a gym,” I say, reaching down to touch my toes — then changing my mind halfway down and resting my hands on my knees. “But I walk a lot.”

    “Great!” says Tony. “On a treadmill? Or cross-country?”

    “Round the shops, mostly.”

    “OK…” he says doubtfully.

    “But I’m often holding quite heavy things,” I explain. “You know, carrier bags and stuff.”

    “Right…” says Tony, not looking that convinced. “Well… would you like me to show you how the machines work?”

    “It’s all right,” I say confidently. “I’ll be fine.”

    Honestly, I can’t be bothered listening to him explain every single machine and how many settings it has. I mean, I’m not a moron, am I? I take a towel from the pile, drape it around my neck, and head off toward a running machine, which should be fairly simple. I step up onto the treadmill and survey the buttons in front of me. A panel is flashing the word “time” and after some thought I enter “40 minutes,” which sounds about right. I mean, that’s how long you’d go on a walk for, isn’t it? It flashes “program” and after scrolling down the choices I select “Everest,” which sounds much more interesting than “hill walk.” Then it flashes “level.” Hmm. Level. I look around for some advice — but Tony is nowhere to be seen.

    The balding guy is getting onto the treadmill next to mine, and I lean over.

    “Excuse me,” I say politely. “Which level do you think I should choose?”

    “That depends,” says the guy. “How fit are you?”

    “Well,” I say, smiling modestly. “You know…”

    “I’m going for level 5, if it’s any help,” says the guy, briskly punching at his machine.

    “OK,” I say. “Thanks!”

    Well, if he’s level 5, I must be at least level 7. I mean, frankly, look at him — and look at me.

    I reach up to the machine and punch in “7”—then press “start.” The treadmill starts moving, and I start walking. And this is really pleasant! I really should go to the gym more often. Or, in fact, join a gym.

    But it just shows, even if you don’t work out, you can still have a level of natural baseline fitness. Because this is causing me absolutely no problems at all. In fact, it’s far too easy. I should have chosen level—

    Hang on. The machine’s tilting upward. And it’s speeding up. I’m running to catch up with it.

    Which is OK. I mean, this is the point, isn’t it? Having a nice healthy jog. Running along, panting a little, but that just means my heart is working. Which is perfect. Just as long as it doesn’t get any—

    It’s tilting again. And it’s getting faster. And faster.

    I can’t do this. My face is red. My chest is hurting. I’m panting frenziedly, and clutching the sides of the machine. I can’t run this fast. I have to slow down a bit.

    Feverishly I jab at the panel — but the treadmill keeps whirring round — and suddenly cranks up even higher. Oh no. Please, no.

    “Time left: 38.00” flashes brightly on a panel in front of me. Thirty-eight more minutes?

    I glance to my right — and the balding guy is sprinting easily along as though he’s running through a field of daisies. I want to ask him for help, but I can’t open my mouth. I can’t do anything except keep my legs moving as best I can.

    But all of a sudden he glances in my direction — and his expression changes.

    “Miss? Are you all right?”

    He hastily punches at his machine, which grinds to a halt, then leaps down and jabs at mine.

    The treadmill slows down, then comes to a rather abrupt standstill — and I collapse against one of the side bars, gasping for breath.

    “Have some water,” says the man, handing me a cup.

    “Th-thanks,” I say, and stagger down off the treadmill, still gasping. My lungs feel as if they’re about to burst, and when I glimpse my reflection opposite, my face is beet red.

    “Maybe you should leave it for today,” says the man, gazing at me anxiously.

    “Yes,” I say. “Yes, maybe I will.” I take a swig of water, trying to get my breath back. “I think actually the trouble is, I’m not used to American machines.”