Free runners commute into Horsham from as far away as Coventry in the Midlands, the County Times can reveal this week.
The sport, known as Parkour, involves moving along an urban landscape tackling various obstacles in the quickest and most efficient manner possible.
Advice had been issued by Horsham police earlier this month after officers became concerned about the safety and damage to buildings’ roof tops.
But David Witchell, a Christ’s Hospital pupil who started up Parkour Sundays - a Horsham based group of athletes who train around the town centre - believes those involved with the sport have been given the wrong image.
The 16-year-old, who just achieved five A*s, four As and a B at GCSE, said: “It’s the exact opposite of using alcohol, drugs and playing on the Xbox.
“It’s physically and mentally good for you. And people think it’s anti-social, but this sport is nothing but sociable.”
Free running partner Mark Woodland, a 16-year-old Forest School pupil, said: “Before I started this I wasn’t a popular kid, I didn’t have that many friends.
“But I’ve met at least 100 new people, it’s a lovely community atmosphere which is surprising.”
The duo say their group is widely known to other athletes outside Sussex, and day visits are arranged to different places across the country via the internet.
“We go to London, and we’ve had two people down from Coventry who say they will take us into their homes when we visit them,” continued David.
Parkour Sundays aim to lead by example, and even hold lessons for people wanting to get involved.
“Kids watch us and ask questions, and the last thing we want is for them to go off and try something when they’re not ready, so we teach them.”
Speaking of the recent police advice, David added: “I can understand why the police don’t like it and the public are concerned about our safety.
“It’s scary to watch, but so is an Olympic competitor racing at such fast speeds.
“We have a lot of respect for the police. Even they understand that we’re not doing anything wrong, but because it’s growing they’re worried so many people are going up [on roofs] and breaking things. We won’t break anything, because if we do, we can’t use it.”
Information about Parkour Sundays and some of the group’s videos appear online at http://www.youtube.com/user/ParkourSundays