Getting up at 6.30am for yoga followed by hiking or biking in Ireland without a pint of Guinness or a plate of chips in sight might not sound like fun, but people are queuing up to do it.

The Body and Soul Experience was conceived by Aidan Boyle who until recently ran “bikini boot camps” in Brazil attracting celebrity clients such as Davina McCall, Mariella Frostrup and even Jade Goody. Boyle describes the experience as a “life transforming active spa vacation designed to tone the body and clear the mind” embracing a healthy low-calorie diet free from alcohol, caffeine and sugar.

Boyle has now returned to his native Donegal to run the same course from Harvey’s Point – a comfortable four-star hotel on the edge of the beautiful Lough Eske.

Being a bit nervous of all this activity and abstemiousness I signed up to a three-night “Renew-U” weekend – Aidan also offers a week-long course for the more hardcore. After arriving and settling into my absolutely enormous room with the hugest TV I had ever seen I joined my fellow detoxers for our first healthy snack - a beautifully made salad and fantastic pulpy juices.

Following a gently-paced yoga class and a soak in a huge lavender-scented bath (run for me by housekeeping staff – I felt very spoilt) we all gathered in the reading room to hear a little about what was to come – just 1,200 calories a day, no alcohol, no caffeine, no sugar, no excess. And a lot of exercise.

Dinner was doll-sized but exquisite – a tiny salad leaf filled with crab salad followed by vegetable soup and then monkfish wrapped in spinach. While not exactly full, I did feel sated.

Next morning the real work began. An alarm call at 6.30am summoned us to an hour of yoga at 7am – slightly more dynamic than the evening before but not too difficult as some of the group were total beginners. After a small bowl of perfectly-cooked porridge with prunes we assembled for our first hike – an 11-mile trek along the Blue Stack Way.

Before we left Aidan handed out lunch – a small flask of soup, a banana and a plum – and we set off in high spirits. The scenery was breathtaking and we were even lucky with the weather – apart from the odd shower, the sun was out allowing us to enjoy the spectacular views.

The group of 12 (11 women and one man) was very mixed – some were keen hikers and some (including me) had not done much hiking at all. Aidan stressed that we would go at the pace of the slowest and I didn’t find the walk as physically hard as I had expected to.

What I did find difficult was trekking after so little food. By lunchtime I had a pounding headache which stayed with me for at least 24 hours and I was also feeling slightly sick. The soup and fruit buoyed me up just enough to get through to the end of the walk and when Aidan produced a box of trail mix at about the halfway point we all fell on it like vultures.

My legs ached so much by the time we arrived back I thought there was no way I would be able to complete another hike the next day. But after a bowl of broccoli soup, a yoga class, a hot lavender bath, a blissful massage and another tiny but beautifully cooked and presented dinner, I actually felt in pretty good shape.

When the alarm call rang at 6.30am the next morning I was disheartened to discover that my headache had worsened. I dragged myself to the yoga class feeling slightly tearful at the prospect of another hike – this one up Slieve League – at nearly 600 metres the highest sea cliff in Europe. But after breakfast of a poached egg with spinach and several painkillers, once I had my hiking gear on and was out in the fresh air I didn’t feel quite so bad.

The walk was much steeper but shorter that the previous day’s hike and I was surprised to find it easier on my legs. Again just before lunchtime I felt myself seriously flagging and although the weather was again mainly good, “lunch time” involved standing in a hailstorm hurriedly gulping down soup.

The view at the top made it all worthwhile and we returned to the hotel for yoga, baths, massages and dinner. That night I went to bed very early – head still pounding.

The next morning was to be our last day and we were treated to a lie-in – our alarms didn’t ring until 7am. After yoga and breakfast we were due to go on a bike ride around the lake. The weather had changed and it was now very windy and rainy and Boyle warned that it might not be a good idea for people who weren’t used to bike riding.

While not used to riding a bike outside of the gym, I thought I would give it a go but only managed part of the circuit. I had finally got rid of my headache but this had been replaced with a nauseous feeling – I had never realised detoxing would be such hard work. I was feeling so rough I couldn’t eat my final goodbye lunch and was devastated – it was three courses, looked beautiful and for the first time all weekend there was even a dessert – apple strudel.

So was it all worth it? Definitely. Now I am home my skin looks great, I am eating smaller portions, drinking less alcohol and sleeping better having totally given up caffeine. I enjoyed the challenge of the exercise, the yoga was perfectly paced, massages fantastic and the setting beautiful. It’s certainly a very different way to spend a weekend, but it’s not for the faint-hearted.

Need To Know Renew U Weekends - prices start from €950 (£600) per person and include 3 nights’ accommodation at the Harvey’s Point Country Hotel, all meals, juices and daily snacks, 2 full body massages, 24 hours supervised activities, 5-6 yoga classes, 3 lavender salt baths, mountain hiking, biking and all taxes. Flights and transfers are not included in the price (UK travellers can fly to Belfast or Derry). Dates: Upcoming dates April 12-15, May 31-June 3. Regenerate and Rejuvenate Weeks - prices start €1,950 from per person. Dates: April 9-14 and May 31-June 6. For more information and bookings visit www.bodyandsoulexperience.com or call 00 353 87 9397821

Flights from Gatwick to Belfast with Flybe start at £24.29 each way. www.flybe.com

Times recommends

• 'New York has lost its edge'
• The UK and Ireland's 25 best Christmas events
• Chalet Chef 2010: the winners