Sitting cross-legged on the sprawling lawn of a Georgian manor house, the backs of my hands resting on my knees, my eyes closed, listening to birdsong, I finally came around to yoga. I’ve tried it before in bland gym classes and in musty community centres, but it was on that mossy lawn in Yorkshire that I could see why people got hooked.

This serenity was not without endeavour. Before it came involuntary groans, voluntary groans, clicking knees, sweating palms and quivering muscles as I tried to keep up with Melinda, the yoga teacher. I thought this would be the easiest part of my three-day retreat, some relaxation between the hiking and circuit training, but yoga is not for sissies.

Melinda’s toned figure and poise is tantamount to the benefits of the sport, if you can call it that, but that physique doesn’t come easy, especially not if you feel half starved and have a splitting headache because your body is craving a latte.

It sounds like boot camp, like we were woken up each morning by a sergeant major and frogmarched before a breakfast of gruel and a cold shower, but at this retreat the authority was subtle, the atmosphere light hearted and the food delicious. The greatest surprise? I enjoyed it.

The retreat is run by in:spa, a company that has hosted week-long detox, weight-loss and fitness programmes in destinations such as Marrakesh and Ibiza, for four years. I joined the first UK retreat, also in:spa’s first short break, regarding it as an opportunity to detox from London life and get my fitness back on track.

I had expected to be joined by 21 bendy yoga junkies, and be the one trailing at the back, but I was surprised by the spread of ages, singles and couples, and expectations. Richard, a hedge fund manager and his wife Donna from London wanted a break from the kids and a health MOT, although it was Donna who was the driving force behind joining the retreat, a recurring theme in nearly all of the couples who were there. June from Durham had dragged Keith along, a retired teacher, because she wanted a weekend break that didn’t revolve around eating and drinking and putting on weight, Leonie from Brighton really was a bendy yoga junkie, and Anthony from Surrey wanted to get fit, but I think meeting a single lady may also have been on the agenda.

The group met on the first night over dinner in the elegant surroundings of the Middleton Lodge dining room. The house is owned by James Allison, a young entrepreneur and eligible bachelor who caused a bit of a stir among the single ladies of the group. He hosts weddings, conferences and now in:spa retreats in his eighteenth century home. He moved in to the house with his parents 28 years ago when it was dishevelled and has recently restored its fireplaces, chandeliers, coving, tiled floors, snooker table and added an outdoor hot tub. The entrance is grand – a gravel drive lined with rhododendrons and wild flowers lead to a wisteria and rose-draped front door. But inside, the antique furniture is a lived in, family photos adorn the walls and there’s no house rules – it was ours to roam for the weekend retreat, or “healthy house party” as in:spa founder Kathryn Brown, who joined the trip, dubbed it.

We stayed in the main house, the bedrooms simply decorated with different themes. Mine had a creaking antique wardrobe and wonderful views over the lawns and countryside beyond. The linen was fresh and the Ren natural toiletries were worth taking home. Only the hot water let some of us down on day one with the rush for showers after the hike, but it was fixed by day three.

After a dinner of spicy lentil soup and roast cod we were introduced to the team. Melinda and Kathryn talked about what we could expect from the schedule, then Nik Cook, a fell runner and fitness expert, and personal trainer Wendy Spence, gave sparky speeches about getting the most out of the weekend, to which Kathryn added that people could relax, sleep and do as little or as much as they wanted.

The first rumblings of dissent came from Helena and John from Gloucestershire, over the absence of “real tea”, although by the end of the weekend Helena told me she’d got a taste for the herbal stuff. John, however, said he’s be stopping at Little Chef for a well-earned brew on the way home.

The next three days had a similar programme; yoga or a jog at 7.30am, breakfast then a hike in the Yorkshire Dales until lunch, a break of a couple of hours, then circuits or some more challenging yoga until 3pm, then a relaxing yoga stretch class before tea (but no biscuits). Yoga relocated, depending on the weather, from the lawn to the oval drawing room, which had an intricate crystal chandelier, grand piano and vast sash windows spilling onto a terrace.

I found it tough at first, and frustrating, but Melinda helped us into the poses as she padded between us continuing her soothing mantra, and I started to get the hang of it. For others the hikes were the highlight, and some of the crowd joined only these each day. Nik had set three routes for the consecutive days, gradually becoming more challenging, which covered less than 7 miles, but in one case ascended 418 metres up Fremington Edge to spectacular views over Swaledale.

Times recommends

• Your Top 10 questions on low cost airlines
• How to hen party in style
• Steaming into Bangladesh