It was a careless mistake at the Kuala Lumpur Marathon eight years ago which first sparked off Peter Loong's passion for barefoot running.

Already an avid runner who had taken part in numerous marathons, his usual routine would be to carry his running shoes in a shoe bag and wear slippers from his hotel to the start point.

"I didn't notice that I had forgotten my shoes until I was in the bus to the start point," the 48-year-old told The Straits Times yesterday.

Luckily for Loong, he ran into Tan Wah Sing, a fellow running enthusiast who was part of Malaysian barefoot running group, Bare With Me Earth Runners.

Loong recalled: "He gave me a 30-minute crash course on barefoot running, the technique as well as some training and tips after I told him (about my situation).

"I ran (barefooted) behind the group the whole way... At the end point, even I was shocked that I made it."

Since then, Loong - who is the chairman of Jalan Kayu Community Sports Club (CSC) - became a strong advocate of barefoot running. He helped to set up the Singapore Barefoot Minimalists, a group of runners who share a similar interest in the running style.

The group, which has a Facebook page with over 800 members, has organised several clinics since 2013, inviting seasoned barefoot runners from Japan.

Running barefoot requires runners to adopt a different running technique.

Instead of landing on their heels first, barefoot runners land on the balls of their feet. Proponents of the technique say this minimises the impact on the rest of the leg, and is less likely to cause injuries.

Because of the different technique, Loong would not recommend new barefoot runners to start off with a marathon .

The 48-year-old explained: "New runners should start by running on the beach, then grass patches, before roads. Try to ask someone experienced to look at you when you run, and make sure your technique is correct."

His thoughts are echoed by two-time SEA Games gold medallist and national marathoner Mok Ying Ren.

Mok, who is managed by ONEathlete, said: "As with any technique, there are both upsides and downsides, mainly risk of injury if used improperly.

"The key thing for beginners is to train progressively."

Loong, who has finished more than 100 races barefoot, has now set his sights on the People's Association's (PA) Harmony Virtual Challenge.

The race, the first of its kind in Singapore, challenges a pair of runners to run a total of 50km, 100km or 150km between them, anytime within the period of July 1-18.

The challenge is part of the PA's lead up to Community Sports Day, a half-day event to be held at various CSCs across the island, with all proceeds going to the Children's Charities Association.

Aside from the physical perks, such as decreased knee and ankle discomfort post-runs, Loong feels barefoot running has also trained him mentally.

He said: "We don't look around when we run. We have to look at the ground and concentrate on the floor in front of us.

"For me, its also a form of mental training, honing your alertness and endurance."