Zumba Fitness with Christine Gonzalez 

Getting in shape has never been this much fun. There are scores and scores of Zumba instructors, so what makes Christine Gonzalez special? Ask her students. They fill up her classes week after week, shedding pound after pound—hardly a surprise when a typical session can burn up to 800 calories. Class always ends with a drill sergeant-style, eight-minute ab routine, and students can also enroll in a Biggest Loser-type program every three months, which includes weekly sessions, nutritional guidance, diet logs, and more.