I’ve never found it easy to exercise – but I need to, so I do. It makes me feel healthier and generally much chirpier about life. Still, it’s a hard slog, and some days it just feels like torture. So I was intrigued to hear about Bodydoctor, a new private gym opening in the crypt of St Peter’s, the church on Eaton Square. Designed to be equally effective for men and women of all ages and levels of fitness, Bodydoctor’s personal training programme promises to help you achieve your personal fitness and health goals in record time.

The gym is certainly pretty swanky – all smooth hardwood floors, brand new equipment and marble bathrooms with stacks of white fluffy towels. But according to the Bodydoctor himself, David Marshall, this is a lot more than just another top-of-the-range gym. Originally a footballer, David found himself with a knee injury that ended his career at age 17. Back then, in the 1970s, gym-goers were effectively bodybuilders; David, by contrast, started practising yoga – admittedly, he was the only man in the class – and quickly realised its potential. Experimenting on-and-off for 15 years, he gradually developed a programme which worked for himself and his friends. By 1992 he had settled on a method: a six-week programme ‘to get back to fitness without being a slave to fitness.’

The Bodydoctor programme is based on the principles of teaching people how to exercise, stretch and align their bodies, with a priority placed on developing core strength. Each trainer works with David for weeks before they’re let anywhere near to his clients: ‘They have to be able to do my work out, my way. They’re effectively teachers, not trainers, and we work hard to make sure clients have the knowledge they need at the end of their work outs.’ The idea is to empower and teach people to do this by themselves – to this end, a whole range of Bodydoctor DIY fitness products, including a book and DVD, are available. And while David admits that his clients often stay beyond the six-week programme, they do so out of choice rather than necessity.

Each session is simple: 15 minutes of cardio warm-up, 45 minutes of one-on-one intensive weight training, and then three 10-minute blasts of high-intensity cardio. The studio has experts in injury prevention and rehabilitation – Pilates, yoga and Power Plate training are all offered – and is also known for its excellent post-natal programme. Above all, David and his team make your workout fun. I left each session in a brilliant mood, feeling ready to tackle my day. And although the workouts were tough, they never felt unbearable.

Enjoyable workouts? In my world, that’s fairly unheard of! As soon as word gets out, I think this place will be inundated with client requests.

David tells me it’s all pretty simple, really: ‘The Bodydoctor method is a programme for putting the body back into balance. It just so happens that this is the ultimate fat shredder and body sculptor. One size fits all – the Bodydoctor method is equally effective for an 18-year-old professional athlete or a 76-year-old football club chairman.’ One thing is for sure, he’s created a brand that promises people the same product whether they’re training at his studios in Primrose Hill, Eaton Square, Sardinia or Mauritius.

The best thing about the Bodydoctor programme is that it promises results. As David says, ‘If you’ve got it to lose, you can lose up to three sizes.’ So successful is his method that David’s client list includes – though he himself will neither confirm nor deny this – Lily Allen, Sophie Dahl, Frank Lampard and, allegedly, Roman Abramovich. (For those who really don’t want to be seen, there’s even a private gym within the private gym.)

David describes the Belgravia studios, officially called the ‘Bodydoctor Health and Fitness New Bespoke Personal Training and Holistic Therapy Centre’, as a ‘one-stop-shop for wellness.’ In addition to the trainers, he has a whole host of staff using the treatment rooms headed by Jonathan Weisfeld, formerly of the Hale Clinic. Nutritionists, facialists and hypnotherapists are all on hand along with the brilliant facial reflexologist Rupert French, who had me feeling like I was floating on air, and the nimble-fingered masseuse Bobbi Swanson, who brings a whole new meaning to deep tissue massage. The idea is that whether a therapist or trainer, everyone working in the studio is a leader in their respective field, making Bodydoctor a true ‘centre of excellence’. Between them, I bet these experts could solve problems you weren’t even aware you had!

The six-week programme consists of 20 one-and-a-half-hour sessions. Bodydoctor is realistic about peoples’ busy lifestyles, and accordingly is pretty flexible with scheduling. There are all sorts of different packages available, including membership for one/two/three sessions per week (some including treatments) and, for people who travel, books of five- or 10-session packages.

David calls this ‘preventative healthcare at its best.’ He continues: ‘I’m proud that the Bodydoctor is the only programme in the world to be approved by a major healthcare company.’ He repeats his mantra: ‘You only look good when you feel good, you only feel good when you are good, and you only are good when you are healthy.’ I’m sold.