WHEN Impact MMA first opened its doors nine years ago, the gym - located on the third floor of the nondescript Shenton House building in the Central Business District (CBD) - only drew about 60 people to its classes each week.

These days, the grungy gym sees weekly crowds of 400 undergoing training in the key areas of mixed martial arts (MMA) such as Muay Thai, Brazilian jiu-jitsu, grappling, wrestling and boxing.

Impact has produced numerous fighters from Singapore who have gone on to compete professionally, most notably Royston Wee, who is, to date, the only Singaporean to compete in the Ultimate Fighting Championship. Wee is currently one of the star trainers at Impact MMA.