People balancing their body by walking on top of a slackline - a thick, nylon-webbed strap stretching between two anchor points – could once be seen only in a circus event.

Now, slacklining is considered an urban sport and it is being promoted in Kuala Lumpur.

It involves balancing on thin, stretchy tape, usually not very far from the ground, and bouncing on a trampoline. It's both fun and healthy, said founder and manager of Slackline Community KL, Helena Foo.

About 50 people have recently taken up the sport. These are the beginners who wobble along the webbing tightrope. Then there are the experts, numbering about 20.

"They leap from line to line, perform somersaults and chest bounces and other astonishing tricks," Helena said of the enthusiasts who took up the sport in 2013.

"This sport can give you a great overall body workout because it involves core muscles, calves, quadriceps and back muscles by merely trying to balance on the slackline and as you take your first steps on the line," she said.

Helena, who is a physical theatre practitioner, said she was hooked to slacklining after having been introduced to it by an English housemate when she was in Liverpool.

She said that Slackline Community KL meets every Sunday at Taman Titiwangsa from 10am to 1pm, and everyone can attend for free.

However, the community charges RM45 per person for one lesson of 90 minutes.

"People usually go through three to five lessons before they can walk a 10-meter slackline," Helena said.