Delphine Lamandé-Frearson tries out the Kensington gym that US celebrities can't get enough of

Any products in this article have been selected editorially however if you buy something we mention, we may earn commission

Equinox ( www.equinox.com ) is the Net-A-Porter of the fitness world; it is innovative, high-end and delivers impeccable, quality services. With years of fitness road-testing behind me, I was eager to check out how the first UK club fared, compared to its upscale US parent clubs.

Housed in the former Rainbow Room, below social hotspot The Roof Gardens, its side entrance off Kensington High Street offers privacy to its many high-profile clients. Stateside, President Obama, Claire Danes, Cameron Diaz and Natalie Portman are all Equinox fans and though I spotted many groomed rich Americans here, no paparazzi were in sight.

If I knew what to expect on my first day (Equinox is a solid, upmarket brand with over 20 years of experience), I was definitely not disappointed, for the 33,000 square foot Kensington outpost is simply flawless.

Think five luxurious fitness studios, each dedicated to specific classes and equipped with the latest relevant apparels for Pilates, yoga, cycling, boxing and cardio; a large cardio and strength suite packed with the most result-driven machines, from Woodway shock-absorbing treadmills to Matrix Stairmaster and Precor ellipticals; from the AlterG anti-gravity treadmill (revolutionary for joints injuries), free and assisted weights to TRX equipment. A super gym it is.

My personal favourite equipment for freestyle training? The manual, eco-friendly Curv treadmill (you use your own body weight to activate the belt and it burns up to 30% extra calories per workout) and the low-impact, all-over conditioning Jacobs Ladder, on which you climb your way to a leaner and stronger body without straining your neck and lower back.

After tasting a protein-laden, gluten-free muffin and a signature health juice at the swanky The Juicery café, where you can also download one of Equinox’s selected playlists, I discussed class options with Assistant General Manager Dan Brewis (a perfect poster boy for Equinox: smart, buffed, polite and discreet).

A quick snoop around The Shop to satisfy my fashionista cravings (I made mental notes of my new fitness wardrobe: LuluLemon coral capris, Mercer and Taylor purple sweatshirt and a silver MZ Wallace quilted bag) and I was ready to kickstart my week of training at Equinox.

Monday: 6.15pm: Shockwave

This 45-minute calorie-blasting, cross-training class uses Indi-Row machines (the smoothest of the rowing machines) for endurance, and body bars and Kettlebells to challenge your muscles. You go from one station to the next repeatedly (six in total) but before you know it, it is over and you leave the class breathless but exhilarated (adrenaline and endorphins create that happy, fitness high).

Tuesday: 1.30pm: Tread & Shred

For this 30-minute class, you hop on a treadmill and the instructor guides you through the high-intensity interval training workout through headphones. It is equally effective whether you want to start running or simply increase your running pace (in my case) as you adjust your own speed and get tips along the way. Post-workout, chilled eucalyptus-infused towels help you cool down faster if you are in a rush to go back to work.

Wednesday: 7.30pm: Barre Burn

You don’t need ballet basics to follow this hour-long choreographed toning class, though if you have then you will be familiar with the isometric movements (stationary, strengthening contractions), the pliés and relevés. Light resistance weights are used to tone up and quick changes of rhythm provide some aerobic work so you burn more calories. You definitely leave the class walking taller and feeling stronger.

Thursday: 6pm: MetCon3

This 50-minute circuit class boosts your metabolic rate and conditions your body all at once with a series of ten exercises repeated three times (hence the name). Armed with 5kg dumbbells, a medicine ball, a step and a body bar, you move through lunges and squats, planks and jumps with one minute to recover between each series.

Friday: 6.45pm: Tabata

This 45-minute high intensity workout is designed to increase your athletic performance with eight repetitions of a four-minute workout, that focuses on a 20-second high-intensity exercise (such as press-ups or lunges) followed by a ten-second rest. It is not for the faint-hearted but you get fast results.

The post-workout experience is equally enjoyable. There are eucalyptus steam rooms to unwind in and the elegant, spacious changing rooms (think walnut wood and porcelain tiling) are stocked up with Kiehl’s toiletries and other essentials (mouthwash and hairspray). I was ready to move in after my first shower.

One of the local yummy mummies told me she leaves her gorgeous offspring at the gym’s crèche (which puts private nurseries to shame) so she can head to the spa after her class to maintain her post-gym glow. The treatment menu is impressive, and lists premium skincare lines such as Omorovicza and Ionithermie so I get her logic.

Membership fees may be on the steep side (£180 per month), but remember you pay for all-inclusive, premium services that will get and keep you fit. Whether you need motivation to exercise or simply to challenge yourself, this is the gym to join as you will never get bored or be let down.

Find Equinox at 99 Kensington High Street, London W8 5SA and contact them on 0207 666 6000.

Make-up by Camila Fez