I am perspiring profusely. Not the moderate sweat of running for the bus or sitting in the sun on a balmy day. We’re talking droplets making their way down my temple and into my ear, a drenched sports bra, some genuine concern for my hydration levels running through my head. Beyonce’s Ya Ya is thudding out of the speakers, and I realise that while I may still technically be in London, fitness entrepreneur Tracy Anderson has successfully parcelled up her West Coast vim and vigour and delivered it to a subterranean series of marble-bedecked rooms in Surrenne, a wellbeing and longevity members’ club that’s opening in Knightsbridge on April 14, with annual membership at £10k, on top of a joining fee of £5,000.