Set to original - form music , the exercises combine dancing and aerobics . Since then , more than 20,000 instructors have been trained worldwide . Its adherents rave about its physical and psychological benefits .
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 .