It’s early December, the day before the latest London outpost of Equinox, the high-end transatlantic fitness club, is due to open. But the five-storey, 32,000sq ft, £200-a-month body temple in Bishopsgate, near Liverpool Street Station in The City, is already heaving. Staff and workmen swarm throughout to ensure that it will be finished on time and to the vertiginous standard the brand tells MR PORTER it sets itself.

Equinox, of course, is slicker than your average sweatbox. It adds polish to perspiring (fashion photographer Mr Glen Luchford shot its latest ad campaign), which makes the sight of protective tape covering the fixtures and fittings at Bishopsgate all the more jarring. There are cavernous changing rooms and a spa, Woodway treadmills specially designed for its Precision Run interval programme and a studio for The Pursuit, an immersive, gamified spinning class specifically tailored to competitive City types. The chairs in the mezzanine-level café are upholstered in grey chalk stripe that calls to mind the traditional uniform of bankers, while the wooden tables have built-in wireless chargers. The vibe is luxurious, but in a resolutely functional, relentlessly productive way.

Mr Harvey Spevak, the executive chairman and managing partner of the Equinox group, which also comprises boutique spin studio SoulCycle and budget gym Blink Fitness, landed at 9.45am this morning from New York, where he lives and mostly works. The 55-year-old Bronx native travels “probably 35 to 40 per cent” of the time; over the next 30 days, he will visit 20 cities, a little more than normal because of the holidays. But Mr Spevak isn’t about to let a busy schedule derail his regimen: “I try to be even more disciplined when I’m travelling than when I’m at home because I know that’s the only way I’ll come out the other end energised and accomplishing what I need to accomplish.”

For example, he ate before he boarded the plane last night, because “airline food is horrible”, and packed nuts for in-flight snacking. He stayed hydrated. When he landed, he immediately jumped on a treadmill, as he likes to when he travels, particularly internationally – “just to get the endorphins going” – for half an hour. “I work out most days for about an hour and a half, about a half hour is interval training on a treadmill and then an hour with my trainer,” he says, and, as he points out, he tries to keep the momentum going when he’s on the road. To this end, his trainer has sent over his full programme so that his diligent client of 15 years can get in a proper workout tomorrow morning even though he’ll be jet-lagged. (He keeps international trips “tight” – this one will last just 36 hours.) After his session on the treadmill, he went to look at a piece of real estate: Equinox plans to increase its three sites in London to 10 within the next five years. Then he came here. It’s now 1.30pm. He’s been in the country for less than four hours.

Mr Spevak doesn’t have time to attend the opening of every new site in the Equinox portfolio, which with the addition of Bishopsgate numbers 105 across the US, Canada and the UK (not counting SoulCycle’s 95, including two in London, and Blink’s 140): just those that have “great strategic importance”. London has long been considered a key market for Equinox, but it’s taken longer than he anticipated to get to where he wants to be, and to find the most prime real estate. That’s partly though because the company has been “disciplined” in that regard; it’s now well positioned for “robust growth”.

A former associate at JP Morgan who set up a chain of stores selling sneakers (he owns “probably” 200 pairs) then ran New York’s Chelsea Piers athletic complex, Mr Spevak joined Equinox in 1999 as CEO and set about scaling it up from its then five clubs, all in the Big Apple. He was hands-on with openings, moving equipment or cleaning glass in the early hours. With a team of “almost 20,000”, he no longer needs to roll up his sleeves, but he still has a tendency to move equipment, and a hawkish eye for detail. On his way into Bishopsgate, he spotted a stretch mat that he deemed too long, and decreed be cut back: “That’ll be done before we open tomorrow.”

Equinox isn’t just a “gym”. Indeed, when Mr Spevak became CEO, he removed it from all newspaper gym listings in order to eliminate any confusion, or association with run-of-the-treadmill facilities. Rather, it’s a “high-performance lifestyle brand”. It’s a line of athleisurely merch, including club-specific styles, as stocked in the shop at Bishopsgate, which also displays upwardly mobile activewear labels such as Castore and lululemon. It’s a quality content platform, called Furthermore; it’s a travel company, Equinox Explore, which last year began leading active retreats to destinations such as Costa Rica’s Pacific coast and Morocco’s Atlas Mountains; a running tour of Florence is among the trips booked for 2020. It’s soon to be a chain of hotels, with new openings in Chicago, Houston and Los Angeles set for 2020, 2021 and 2022 respectively. It’s hard to imagine any mere “gym” doing likewise.

On a scale of one to 10, feedback on the first Equinox Hotel, which opened in August at the opulent Hudson Yards development in New York, has been, Mr Spevak says, “10-plus”. Even Mr Bernard Arnault, the chairman and CEO of luxury conglomerate LVMH, declared himself impressed by the attention to detail. According to Mr Spevak, guests love that the hotel gym is a flagship Equinox club, that vitamin drips are available on room service, that as well as traditional pampering the spa offers performance treatments such as cryotherapy, infrared sauna and a wave table, which purportedly delivers the restorative effects of three hours of sleep in 30 minutes via “harmonic resonance”.

Even the martinis in the hotel’s Electric Lemon bar are “high-intensity”; the local, seasonal and nutritional food meanwhile is by award-winning restaurateur Mr Stephen Starr. Mr Spevak starts his day with two protein shakes, one either side of training, and predominantly eats healthy, organic and plant-based, but he occasionally relaxes his dietary discipline for a slice of pizza, which he jokes is “a separate food group”; he doesn’t drink much, but enjoys high-quality tequila, which is “some of the cleanest” alcohol.

This morning, Mr Spevak received a text from a recently retired NFL Hall of Famer “who absolutely loved above everything” the sleep experience in the hotel’s soundproofed, air-purified rooms. Touching the button marked “Quiet, Dark, Cold” on the in-room iPad triggers complete blackout and drops the temperature to 66ºF (just under 19ºC), which research indicates is optimal for rest. Not coincidentally, Mr Spevak, who’s big on sleep, sets his thermostat at home to the same figure. As part of its Tier X “personal training and lifestyle management programme”, Equinox offers sleep coaching. Mr Spevak gives short shrift to masters of the universe who claim to function on a sub-optimal four or five hours.

Health is the new wealth, as Mr Spevak also says, and the experience economy is booming, to say nothing of the £4.5 trillion (as of 2018) wellness market, which is enlarging at twice the rate of global economic growth. His 1999 vision of a high-performance lifestyle brand was therefore remarkably on the money, even if, as he admits, it was mostly gut instinct (which he follows a lot) and his feeling that demand was accelerating was “a contrarian point of view at the time”. Investors suspected that it was a “fad business”; landlords were similarly incredulous. Now Equinox is a sought-after keystone tenant for new developments, and the proximity of a club raises nearby real-estate prices. Members have been known to move to be closer to one.

The “inflection point” for wellness was, according to Mr Spevak, the worldwide recession in the 2000s, when people started investing more in self-care. And with its 2011 purchase and proliferation of SoulCycle, Equinox catalysed the boutique fitness explosion, which has changed the industry as dramatically as a before-and-after body transformation and conditioned gym-goers to pay a premium for premium. He doesn’t foresee any downturn: if anything, another recession would open up more real-estate opportunities.

There has been controversy, though. There were calls for a boycott of Equinox and SoulCycle after it came to light that Mr Stephen Ross – the chairman of Related, which bought Equinox in 2005 and is now listed as a minority investor – was holding a fundraiser for President Trump. While Mr Ross has ties to other companies, the blowback was particularly evident at Equinox and SoulCycle, both of which have a more liberal-leaning urban clientele base and have both actively supported progressive causes in the past. SoulCycle sign-ups that month were reportedly down 13 per cent year on year and Equinox’s own customer numbers fell by two per cent. Mr Spevak’s response was to write to members, reaffirming Equinox’s values of “equality, diversity, inclusivity, integrity, empathy and mutual respect”. And despite this setback, he remains bullish about future prospects: Equinox, SoulCycle and Blink will all launch in Dubai next year. Demand is accelerating around the world: “I think you’re going to see there’s continued discretionary income for anything that’s going to help you feel better, look better and have more energy to go about your pursuits.”

With non-stop meetings, calls and emails seven days a week, and a “big responsibility” to his team to continue to grow the business, Mr Spevak’s “regen”, in Equinox parlance, consists of sleep, cryotherapy and a Hypervolt percussion massage device (a bestseller in the clubs’ shops). Once a week, he has a vitamin drip at his desk during a meeting: “It really helps with recharging the batteries.” He doesn’t believe in work-life balance, as “there’s no such thing” as turning off your phone (not literally, but work doesn’t sleep). “There are times where I definitely turn it off, because that's important,” he says. “Not as much as I should, but to me, I’m engaging with the brand seven days a week because I love it.” He attributes a big part of his success to following his passion.

If he does turn off his phone, then it’s to hang out with his twin daughters or watch American football. He also loves a good movie: for his flight back tomorrow, he has downloaded The Irishman, Mr Martin Scorsese’s latest mafia epic. The film’s running time is a marathon three-and-a-half hours, but doubtless Mr Spevak will get through it quicker.