From the narcissistic gym rat to the Lycra-loving cyclist, our offices are awash with these sweat-sodden fitness fanatics.

Sport and your professional life rarely used to intersect. Yes, there was always the possibility you might be roped into some corporate golf foursome or that, once a year, you’d have to find new and convincing ways to lose to your boss at tennis, but beyond that, nobody really cared about your extra-curricular athletic pursuits. Why would they? What a man did with a pair of Nikes in his own time was very much his business and no one else’s.

Times have changed. You can blame marathons or gym culture, after-work softball leagues or good old-fashioned virtue signalling, but in every office across the land, you will find sweaty colleagues arriving in cycling gear, or with ostentatious sports bags, yoga mats or football boots in hand, ready to be slung under desks and then withdrawn with a flourish as lunchtime rolls around. If health is wealth, then the modern office worker likes to give every impression of having just scooped a six-figure bonus. But the office sportsman is a complex genus, and in 2016 he comes in many different forms. With a little help from MR PORTER, we can start to work out who they are and what makes them run.

This guy is impossible to avoid. Literally, he’s massive; clogging up corridors with his gigantic lats, traps and delts (his terms) and the kitchenette with his protein shake paraphernalia. You’ve gradually come to the conclusion that what everybody else in your office considers “the working day”, he views primarily as recovery time from his long lunchtime gym sessions. There he is, sat at his desk, exchanging dubious bro-science advice on power-lifting messageboards while gulping down some murky-looking super-greens pond sludge and scarfing boiled meat from Tupperware. But for all his efforts, he looks kind of... weird. Like a metrosexual Uruk-hai from Lord Of The Rings. His T-shirts are practically sprayed on and, although he’s undeniably hench (again, his term) from the waist up, his tell-tale baggy trousers hint at the bandy chicken legs of someone who’d pull their hamstring if they had to run for a bus.

You’re actually kind of worried for this guy. He just won’t stop. Specifically, he won’t stop spamming your office with emails asking that you all sponsor him for yet another sporting event so extreme and painful in nature that you wonder if he’s trying to do penance for some horrific past sin. Marathons. Triathlons. Tough Mudders. Cross-Channel swims. Ultra-marathons. If there’s something that the human body isn’t really meant to do, you can guarantee he’ll be planning to do it (and that he has the JustGiving page to prove it). Does he have a catalogue of very niche, very boring injuries? Absolutely. Does he want to talk you through each one in extreme detail? You bet. He wears a gigantic GPS-enabled watch and makes sure not to quite wash off the race number on his forearm, just in case you didn’t know what he’d been up to that weekend. Although you do. Because he sent you another bloody email about it.

A highlight of his life was the time he won a beer pong tournament in college and he’s been stuck in a state of arrested development ever since. Even though he’s now deep into his thirties, everything – literally, everything – can be re-imagined as a game to him, albeit a game he absolutely has to win. Did you just catch different elevators down to the ground floor? If his arrives first, he’ll be rubbing your face in that fact for the rest of the day. After-work drinks? He’s the guy trying to organise a beer-mat-flipping contest between marketing and accounts. You’ve never actually got to know anything about him, despite having worked with him for several years, because he spends every waking moment trying to engage you in a game. He lives for locker-room banter (#bants) and was once cautioned by HR for playfully tweaking a colleague’s nipple. Still, for all that, he suspiciously manages to avoid playing any actual... y’know... real-life sport. Niggling injury, apparently.

You know this one. He had trials for an ever-increasing number of professional clubs as a young man and was, the way he tells it, a real prospect. Only then he “discovered girls” and, judging by the size of his paunch, he chanced upon food and booze at the same time. He set up your office five-a-side team, partly in a bid to lose some weight, but also so that he can wheeze around an astroturf pitch once a week screaming incoherent coaching slogans at you (“TRIANGLES! SQUEEZE! DROP, DROP, DROP!”) while doing a lot of pointing and fiddling with his gigantic proto-Robocop knee support. You get the distinct impression he regards this all as just the preamble to the real action, which is to say, gulping down as many pints of beer as he possibly can before his wife starts calling to ask where the hell he is.

He commutes to work on a carbon-fibre bike that cost more than your car, and you swear to God he has a photo of it as his smartphone screensaver. Every day, without fail, he arrives in a black fury because of some “idiot driver” who, he claims, almost ran him over, although the footage he then spends the next hour tying to recover from his GoPro helmet-cam never quite seems to back his side of events. He struts around the office in religion-revealing bodysuits, looking a bit like a member of the X-Men whose special power is PowerPoint presentations. Then he gets changed into a crushed suit and shirt that he stuffed into a backpack. Like all Middle Aged Men In Lycra, he has a serious kink for kit, and you’ve started to notice he’s been taking furtive delivery of an increasing number of breathable sweat-wicking antibacterial merino cycling jerseys in the office. This is so his other half never finds out about just how much he’s spending. Which is a lot.

Every year, he politely declines to join your office Fantasy Football league. He just smiles and shrugs whenever the chat moves on to sporting matters and gives every impression that he’s never done any physical activity that involved anything beyond breaking into a brisk walk. It’s almost as though he’s subtly trolling the rest of you. And yet, the time he reluctantly agreed to make up the numbers for an after-work kickabout, he turned out to be... amazing. He just pitched up in borrowed old trainers, ate a sausage roll on the touchline and then proceeded to run rings around everybody. Left foot, right foot, the lot. He doesn’t care about sport and he doesn’t know about sport. He just happens to be quietly amazing at it. The ultimate dark horse. There’s one in every office.