Lift: The Movement in Shoreditch, east London, is not your typical fitness studio, which is to say a nightclub cum pain cave. Minimalist and monochrome, the soul-soothing, Instagram-baiting space is filled by natural light, plus gymnastic rings on the ceiling, stall bars on the walls and, depending on the time of day, ju-jitsu mats on the floor. (Professional martial artists in various disciplines are among the blue-tick clientele.)

“We don’t have disco lights or music,” says Lift co-founder Mr Angus Martin, who is decked out in Vans Old Skool sneakers and a skater-fit own-brand T-shirt rather than the usual skin-tight, gun-showing activewear. He got into bodybuilding and powerlifting as a keen rugby player growing up and tipped the scales at 17 stone. (He’s now 13 stone.) The toll on his body was heavy. He had the elbows of a 55-year-old at the age of 24. Undoing the damage has taken one operation, four years of rehab and constant, ongoing maintenance.

Now Mr Martin’s passion is fixing other people’s problems that, he says, conventional training exacerbates by over-developing your front-facing beach muscles. Bodybuilding is “the worst thing you can do”, he says. It only compounds your anterior dominance (rounded shoulders), one of the deleterious effects of sitting down all day. Lift is rare among fitness studios in offering a class, Re-Gen, expressly to counteract the dysfunctions caused by sedentariness. It’s also one of the few where you’ll be told not to train if you can’t (yet) perform exercises properly and safely, rather than high-fived for staggering through.

“If the goal is to make it through 45 minutes without being injured, then well done,” says Mr Martin. “But if it’s to build on a foundation and develop yourself physically and mentally, then that’s rubbish.” The immediately gratifying endorphin rush and quick fix of trendy Hiit classes are, in his articulation, “sugar” that leads to an inevitable crash. Lift is a “movement” away from junk workouts to something more nutritious. A slow-fitness revolution, if you will. Progressing to skills such as handstands and muscle-ups is painstaking, but restores proper, healthy function, from which eye-pleasing form follows.

You will find barbells and kettlebells at Lift, but they’re primarily employed for loaded mobility. “Passive stretching is very ineffective,” says Mr Martin, who compiled the circuit below to reinforce the “three pillars” of hips, spine and shoulders. You might complete three to five rounds, depending on your time and how well you recover between reps. Advanced movements should be done more sparingly and loaded mobility approached with appropriate caution. “Listen to your body,” says Mr Martin. And go slow.

Do not attempt this if you have pre-existing spinal problems. That said, this gymnastic mainstay is not some kind of ill-advised rounded-back deadlift. Instead, the J-curl lengthens and strengthens your posterior chain, aka the muscles on the back of your body. Start with a very light weight. “It’s essential for the handstand, L-sit and touching your toes,” says Mr Martin. Holding a (light) kettlebell, stand with your feet together on a block. Curl your spine from top to bottom, vertebra by vertebra, contracting your quads to help you go lower. Feel the stretch, then pull back up through your posterior chain.

This pretzel position is “easily achievable with the right prerequisites”, says Mr Martin. It’s also fundamental for hand balancing and not becoming a hunchback. Warm up thoroughly with exercises that open your shoulders and activate your posterior chain with your arms raised (eg, overhead lat stretches, butcher’s block, Supermans). Elevate your feet with a block to take pressure off your lower back and ask a helpful spotter to lift you into the position. Then drive through and away from the block. “As your range improves, reduce the height of the box until your feet are on the floor,” says Mr Martin.

Another exercise that looks – and sounds – painful to the untrained eye, the German hang, as it’s also known, is more therapy than torture, particularly for desk workers. Warm up with shoulder extension stretches (eg, table tops), then pull up on the rings and pause at the top. Bring your knees to your chest then rotate backwards while straightening your arms like “a scuba diver rolling off a boat”. With a spotter to support your knees if needed, gradually lower as far as you can, then extend your legs if possible. German-hang for a few seconds, then reverse: a literal slow-fitness revolution.