The music is thumping an infectious Latin American beat. The sweat is pouring as the crowd, moving as one, shimmies and shakes, weaves and waves. It could be Havana but, in fact, it’s Barcelona. This is ZUMBA® FITNESS, the fitness dance craze that has taken the US by storm and is now poised to take over the world and especially Spain with its lust for Latino music, in an unstoppable rip tide of wild abandoned enthusiasm.

It all started simply enough in Colombia in the Nineties when aerobics teacher Beto Perez forgot his usual music and had to improvise around the music he had in his car – traditional Latin salsa and merengue. The class was a huge success and Perez realised he was onto something, merging aerobics with dance to a lilting Latin beat. He moved to the US and the Zumba bid for world domination began. There are now more than 20,000 instructors teaching Zumba® fitness in 35 countries.

The principle behind Zumba® fitness is incredibly simple: get fit, have fun. That’s it. There are no complicated moves to learn and you don’t need the co-ordination of a standard aerobics class – or the partner you’d require for a traditional salsa class. Best of all, the music is so infectious that you barely even notice you’re exercising. ''It’s like being at a party,’’ says JDA owner and lead instructor Juliya, ''It is easy to follow so people don’t have to think too much about what they’re doing and can just get into it. And the music makes you want to dance’’.

A standard one-hour Zumba® class uses four basic rhythms based on simplified versions of Salsa, Merengue, Cumbia and Reggaeton (mixed up with a bit of Mambo, Flamenco, Rumba and Calypso). ''It’s a cardio-based workout which also helps tone and sculpts the body. It’s a great way to lose weight, increase strength and co-ordination, and to foster self-esteem and pure happiness. That is why so many people love it and get addicted to it.

People certainly get incredibly enthusiastic, nigh-on evangelical, about Zumba® fitness. ''Imagine a Mexican wave at a football match – that’s nothing in comparison with the atmosphere at our hall each week. It’s total, powerful, mind-blowing energy.’’

There’s a Zumba® fitness for nearly everyone, whether you’re 17 (clad in clingy dance gear) or 70 (firmly in baggy T-shirt and bottoms). Zumba Gold classes are aimed specifically at older people (you can even do Zumba sitting in a chair); we also have a new Zumba® fitness Kids programme.

However much you might baulk at the idea of shaking your booty to a swinging Latin beat, it seems that in the coming months no one in the world is going to be immune from Zumba® fitness. In fact, don’t even try to resist: give in, get up and join the party.