She may be only five years old, but Isabelle Pak is already among the ranks of Singapore's adrenalin lovers. The thrill-seeking tot loves the downslope rush of the luge at Sentosa.

She straps on a helmet, grips the steering handles tightly and is off, accompanied by mother Irene, 41, who rides behind and steers the course.

Part go-kart, part sled, the luge is a gravity ride for all ages with a braking system that allows you to control how fast you travel downslope.

The helmet gang includes father G.K. Pak, 44, who works in the finance sector, and even Isabelle's grandmother, Madam Janet Goh, 66.

Mrs Pak, a housewife, says: 'We like it so much we've even bought helmets.'

She adds: 'There are many possibilities for outdoor fun in Singapore. People just think some things are too touristy and don't bother trying them.'

Indeed, while there are no mountains to scale or jungles to explore here, people are warming up to the great outdoors, which include a host of activities from water sports to tree-top obstacle courses and laser combat missions.

The alfresco antics cost anything from $10 to $50 and outdoor fun-seekers seem happy to fork out the money for the excitement of a new challenge.

According to Mr Lyndon Thomas, general manager of the Sentosa Luge and Skyride, the attraction has seen an annual increase of 15 per cent in business since it opened in 2005.

At tree-top obstacle course Forest Adventure in Bedok Reservoir Park, its managing director Stephanie Besse says that it opened in August 2007 and received 28,000 visitors last year.

She adds: 'We expect this number to increase as Singaporeans may travel less this year due to the economic downturn and therefore seek adventure here.'

Ms Mabel Hui, 29, who went for her first Forest Adventure session last week with two friends, welcomes the trend of outdoor fun here.

The private tutor says: 'Singapore should have more of such adventure activities for people. Otherwise, it's very boring.'

And home-grown companies such as AdvenTOUR, which was set up last year, are answering the call. They are specialising in everything from obstacle courses to kids' camps, and combining outdoor activities in a package, offering more bang for your buck.

School teacher Tay Huiping recently took a group of 40 primary school pupils on an afternoon of kayaking to kelongs at Pasir Ris organised by AdvenTOUR.

Says the 33-year-old: 'Most vendors offer only kayaking in reservoirs or out at sea, but since AdvenTOUR had a kayaking-cum-kelong activity, I thought it was an interesting experience for my students.

'I'd definitely recommend this to friends and families as well, not just for school outings. There are always things to do if you care to look hard enough.'

Adrenalin junkies craving more hardcore action can also consider paintball, a combat mission-type activity where opponents take cover and fire paint pellets from rifles at one another.

Despite the ugly bruises that form when hit, regular paintballer Jason Chu, 29, a civil servant, explains the kick: 'It's an opportunity to experience something different from other sports such as football.'

For those who prefer to make a splash, there is cable skiing, a water sport similar to wakeboarding, except the rider is pulled by a cable and the activity takes place in a big pond.

Sounds easy? Not when you throw in learning how to balance and not fall over around sharp bends, or attempting deft mid-air stunts on floating ramps.

Mr Nigel Ong is a regular at Ski 360, a cable-ski facility at East Coast Park. The education administrator in his 40s says: 'It's a wonderful escape from normal life in Singapore.

'Here, only 20 minutes away from anyone's office, is a fantastic environment to relax.'

Another water-lover is Mr Timothy Chia, a trader and part-time water-sports coach, who teaches mainly at Pasir Ris and East Coast beach under the Water-Venture arm of the People's Association. WaterVenture promotes outdoor community sports at various water venues islandwide.

The 45-year-old sums it up: 'Foreigners have told me that we have fantastic water sports facilities in Singapore.

'At the end of the day, it all boils down to whether you can be bothered or not.'

This article was first published in The Sunday Times.