Stretching their fingertips to the reddening sky, hundreds of yoga devotees rolled out their mats on the runway of Bangkok's main airport Saturday, practising their downward dog as early morning flights rumbled overhead.

The unusual event on the airport's third runway -- which is still under construction -- saw the workout paired with beverages as participants were offered coconuts, iced teas and water to incorporate into their routines.

Some 500 yoga-goers and camera-ready influencers began arriving at 5:00 am, making their way in the dark to their mats on the runaway.

As the sun rose, yoga instructors guided the group through two workouts, cheerily enthusiastic despite the pollution, industrial setting, and occasional flight roar.

"Today is going to be very special," an instructor blared, before urging participants to "put your coconut in the air!"

"Feel like a beautiful bird," she said, as a plane rumbled along the concrete and lifted into the air behind the participants.

While many present were influencers -- and perhaps more focused on getting the perfect shot than the perfect lunge -- most seemed to have come for a laugh.

"This was something fun, this was a nice event," said lawyer Rugeradh Tungsupakul, attending with a friend.

"Right now, because of our jobs, we are too busy to go to a yoga studio," she told AFP.

Although Rugeradh was worried about pollution -- a perennial issue in smoggy Bangkok, which regularly ranks among the world's most polluted cities -- she said they had checked the air quality before arriving.

"Right now, it's not too bad," she explained.

Although there were a few men scattered in the crowd, the workout was dominated by women.

Most were clad in the ubiquitous yoga uniform of black leggings and cropped white t-shirts -- in this instance emblazoned with the word "BREW" for Brew Yoga which organized the event.

- 'Why not?!' -

"This is a very special event for me," said instructor Pavadee Komchokpaisan, 30, adding it was the first time yoga had been done on the runway.

"We have so many people come here to just join the yoga class, and take a picture on a runway," she told AFP, praising Bangkok's yoga community.

One of those receiving instruction was Precious, who has lived in Bangkok for the past four years, and said she was invited thanks to her Instagram-famous cat Ernest.

"He's been to Switzerland, Botswana, South Africa, so obviously this seemed kind of appropriate," she told AFP.

She figured she was unlikely to ever be asked to do yoga on an airport runway again.

"Why not?!" she asked.