Doing yoga in 40C? It got me fired up

In 2008, when tennis player Andy Murray beat world number one Roger Federer, he credited Bikram yoga with his success. Suddenly everyone was at it and I was intrigued. I was introduced to Olga Allon, the 33-year-old Glaswegian who owns the studio that Murray attended. Allon, a mother-of-three, encouraged me to try a class.

I over-researched my subject, working myself up into a state of panic. The first lesson can be tough and it is not uncommon for people to feel dizzy and/or nauseous. I broke out in a sweat just thinking about it.

But Allon, who now lives in north London, reassured me. She told me to take it easy and just sit down if I needed to. "Most people have this feeling that the heat is something to be scared of," said Olga, who owns two studios in south London.

"But the heat is there to support you and help you in the postures. It's better to acclimatise. Don't try and do too much. If you need to leave the room, do so."

I followed Allon's advice and was pleasantly surprised. This was unlike any yoga I had ever done and the heat, though intense, was not unbearable.

Olga explained: "We use a fresh air system, so it's not stifling. The humidity helps you because the sweating lubricates your joints and muscles so you can move more freely.

"After the first few times generally the heat will stop bothering them. More often than not people start complaining that it's not hot enough!"

It was 10am on a Thursday and the room was packed with men and women of all ages. Olga had said that Elle Macpherson was known to drop in, which was far from inspiring. The last thing I wanted was to be puffed out, red and sweaty amid a crowd of supermodels and celebrities.

But it was not like that. Everyone focused on themselves, their bodies and breathing. Everyone was sweaty… (and Elle did not show up).

"Though we do see quite a few celebs, they muck in with everybody else," says Allon.

"The class is incredibly challenging. It teaches you how to stay focused and calm in challenging situations. Whether that's Andy Murray applying that to his tennis or me preparing to give birth."

Though not a franchise, Bikram studios have to be licensed and approved by the guru himself. Allon, a qualified architect, became involved almost by accident - she stumbled across a Bikram studio on her way home from work one day.

"From the first class I was completely blown away. I found myself spending my days at work desperate to get to my yoga classes in the evening.

"Eventually I decided to marry my two loves - yoga and architecture - by opening my own studio."

She opened her first Hot Bikram Yoga studio four years ago, another in 2008 and is planning a third for later this year.

"Bikram is massively popular. You can get everything you need out of this work-out: cardiovascular, weight loss, toning, relaxation and meditation," says Allon.

"Everybody comes with their own reason and comes out with different ways that it's benefited them."

Like Allon, many who try it go on to develop the "Bikram bug".

"You feel so good. When you first start coming you really have to drag yourself there, but once you get into it you start feeling that you need to get back into the heated room!"

Though it may sound like an extreme form of fitness, most healthy people can give Bikram a go. All participants complete a medical form and anyone with concerns should consult a doctor first.

"Whatever the level of your fitness or flexibility, you can get involved in a class," says Allon.

"It's accessible to anybody - whatever age, size or shape they are."