A parkour coach on Tuesday advised against training on rooftops, a day after a teenager was believed to have plunged to his death while doing the extreme sport atop a building in Tsim Sha Tsui.

Lo Chun-chung from the Hong Kong Parkour Association has been teaching the sport for more than a decade.

He told RTHK training is usually done in playgrounds or parks, but some people have misunderstood the sport after seeing popular online videos.

He said a lot of people are unaware of the behind-the-scenes preparations in a lot of the parkour videos they see .

"The most popular videos show the best of the performers; and most people don't completely know the preparation and how they train and how they practice before they film the videos, so this may cause misunderstanding," Lo said.

Training in playgrounds or parks, he added, often involves a parkour practitioner - or traceur - trying to move between obstacles quickly by running or jumping without equipment to assist them.

"The obstacles there are more crowded so we can practice different techniques in the same place," he explained, adding that the presence of a coach and a companion is advisable.

Lo said even the simplest tricks in parkour may involve years of training and traceurs have to familiarise themselves with the obstacles before each performance.

"We need to practice our agility and our body control to adapt to the environment."

The coach also said obstacles should be checked for their stability and potential danger, such as sharp edges, before any parkour training or performance.