Back in the 1980s, aerobics classes and leg-warmers (a type of sock that fits over the caves) were imm8hsely 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 5 right now. Which ones would you like to try? If you love to dance and want to have fun with fitness, try Zumba. fitness immensely popular dance program dance moves set to energetic music. It's 10 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 "zumbawear" clothing that has takan off.