Back in the 1980s, aerobics classes and leg-warmers (a type of sock that fits over the calves) were immensely popular. In the decade before that, bodybuilding was all the rage and Arnold Schwarzenegger was a huge icon for young men. The fitness world is always moving, and trends come and go very quickly. Here are three of the most popular fitness trends right now. Which ones would you like to try? If you love to dance and want to have fun with fitness, try Zumba. Zumba is an immensely popular dance fitness program featuring Latin-inspired dance moves set to energetic music. It's been called the "world's biggest fitness party" by its followers, with over 14 million people taking weekly classes, four million Zumba DVDs sold, and a line of ae "Zumbawear" clothing that has taken off. The concept of Zumba came about by mistake, thanks to the quick thinking of a fitness instructor named Beto Perez. He was about to teach an aerobics class in his hometown of Cali, Colombia, when he realized he had forgotten his aerobics dance music. He only had one cassette tape with him which was full of Latin music. "I improvised," he said, "and that was the beginning of Zumba." Instead of traditional dance fitness classes where steps are counted out lound to the beat of the music, Zumba has a free-flowing and party-like atmosphere. This proved popular with people who were fed up with working out, and zumba moved from just another fitness fad to a true fitness phenomenon.