ALPHARETTA , Georgia ( CNN ) -- Latin music pulses from the stereo as 40 women jump , shimmy and sway to the beat . Zumba is the most popular exercise class at one suburban Atlanta YMCA . It 's not a dance club . This is a regular morning exercise class at the YMCA in Alpharetta , Georgia . It 's called Zumba . Part dance , part aerobics , Zumba is an hourlong routine that works almost every muscle in the body . `` It is dance fitness , '' explained Stephanie Maxim , one of two class instructors . `` We teach them moves that you can see on 'Dancing with the Stars ' : salsa , mambo , cha-cha , and we put it into a group fitness format . '' `` It 's not like a workout , '' explained Diane Walterstiel , 55 , of Alpharetta . `` Before I come , I 'm tense , but when I leave , I could kiss the world . '' Nearly a year after being introduced at the YMCA in suburban Atlanta , Zumba is the most popular exercise offering at the facility . Alberto Perlman , co-founder and CEO of Zumba Fitness in Hollywood , Florida , was n't surprised when the concept took off not just in the United States but around the world . `` We turned exercise into a party , '' Perlman declared . `` Zumba broke some of the rules of fitness . We used music in the original form instead of using step counts . '' Perlman , whose background is in marketing , teamed up with Colombian dancer and choreographer Alberto `` Beto '' Perez in Miami in 2001 . `` One day , Beto forgot his aerobics tapes , so he played his salsa and meringue songs during class in their original form , '' Perlman said . `` People went crazy . They did n't feel like they were in a class with a drill sergeant . '' Perlman said Perez decided to call the exercise Zumba , after the Colombian slang word meaning to buzz like a bee or move fast . Zumba is now a brand name . Since 2003 , Perlman 's group has trained 20,000 instructors around the world and sold more than 3 million DVDs on the Internet and through infomercials , he said . Heather Bleakman teamed up with Maxim to teach the Georgia YMCA session . She called the class a form of therapy . `` We see women change , '' she said . `` We see their faces light up . '' Bleakman stood at the front of the room and offered a high-impact version of Zumba for those who could keep up while Maxim focused on a slower low-impact routine . Maxim warned participants at the beginning of class to modify the exercise to fit their needs . She added that wearing proper footwear is one of the best ways to guard against injury . `` In Zumba , we do a lot of pivoting , so you 've got to have a shoe that has more of a flat base so you can move , or you 'll feel the torque in the knee , '' Maxim cautioned . Lilieth Burke , 48 , of Alpharetta started attending Zumba classes a year ago and kept coming back because she appreciated `` the simple composition of dance moves . '' Unlike other exercise workouts she 's tried , `` Zumba is not a punishment , '' she said . Burke summed up the benefits : `` I feel fit , I sleep better , I feel better , I feel younger , and I feel I can live another 48 years . ''
Set to original-form music , Zumba classes combine dancing and aerobics . Since 2003 , more than 20,000 instructors have been trained worldwide . Zumba adherents rave about its physical and psychological benefits .