EAGLE COUNTY - Something odd is going on in the fitness room at the Aria Club & Spa in Vail.While in the main part of the gym, people are dutifully sweating on treadmills or grunting their way through weight sets, through the glass doors of the fitness room, you can see a roomful of women jumping and dancing wildly, occasionally collapsing into laughter. Did a dance party break out during an aerobics class? Almost - it's the Zumba class, a recent workout craze based on Latin dance.You may not think of head banging, hip swinging or a graceful plie as exercise, but an increasing number of danced-base workouts are blending the fun appeal and rhythm of dance with the intensity and specificity of an aerobic, muscle-building exercise.The advantage of using dance as a workout is that the fun activity takes out some of the work some associate with exercise, said Aria Club trainer and Zumba instructor Jennifer Roberts."I have people who don't want to be on the treadmill at all," she said. "With dance, you're working out to something with a beat, so you can't do half time. If we're jumping to a song with 32 beats, you can't help but jump that many times, and you make it your own with how high you jump."

Avon resident Kelly Lemon Vizcaino has always enjoyed dance from jazz class as a kid to Zumba classes now at the local gym. While living in Ecuador, she said she picked up salsa, Bachata, Merengue, and other latin dances."At the end of the night after dancing all night, I'd be sore," she said. "It's like a continuous cardio workout when you're moving three or four hours."Many dance workout concepts have come from the idea of making dance accessible to everyone, regardless of their musical or artistic background. Dancing with the Stars popularized the idea, and now you can find anything from hip hop to belly dancing workouts on DVDs, on TV and at the local gym.Jessica Jorgensen, a dancer and teacher at Pure Barre studio in Edwards, said that dance workouts appeal to people who are intimidated by the gym."A lot of women like to go take a class because they have a hard time motivating themselves to go in to the gym. They go in, and they don't know how to use the equipment, they don't know what exercises to do, and for how long," she said. "(With dance) you're in a class, you have instructors, and the hour flies by. Also, dance creates a lot of poise and self confidence, and you can see results so fast. It's really addicting."

Some workouts, such as Zumba, focus on the energy and fun of dance. As its slogan goes, "Ditch the workout, and join the party."Lemon Vizcaino, who has done a Zumba class for a couple years, described it as "dancing on steroids," with high intensity movements to different genres of upbeat music. Within the hour class, Roberts said she usually fits in 10 to 12 songs and structures the class into an interval workout, with intense spurts of movement followed by recovery."The intervals get your heart rate is shooting up," she said. "We'll do moves from meringue, salsa, Cumbia - I'm even working on a Greek-themed one. Whether it's Pitbull, Jennifer Lopez or Shakira, I make sure every muscle group is met. I also teach weight training and spin classes, and this is definitely the one when people have the most fun."Lemon Vizcaino said that besides being fun, she knows that she'll be sure to get a good workout in if she goes to Zumba class. According to Roberts, it's possible to burn more calories doing Zumba than a spinning class."It's a very intense workout if you put all of your energy into it," Lemon Vizcaino said. "I'm pretty active. I snowboard and hike, and sometimes I'll do a workout in the gym and then go to Zumba. However, I know I could just do a Zumba class and get a full-body workout."

Ever look at long, lean ballet dancers and wonder how they achieve that flexibility and strength?Some dancers have reasoned that you don't have to enroll in dance academy to reap the benefits of ballet.Melinda Roy, a former principal dancer for the New York City Ballet, helped develop one of the first ballet-based workouts. The New York City Ballet Workout was originally introduced as a book, and later as a DVD and a health club class."Ballet dancers are some of the most incredible athletes, so we wanted to make a workout that was available to the public," said Roy, who was in Vail during the Vail Dance Festival teaching a ballet camp. "Ballet incorporates every tissue and fiber. Also, your mind is a major muscle, and that is completely engaged at all times. It gives you balance, strength and flexibility. You can tell a dancer walking down the street from their carriage and posture."Other workouts, such as Pure Barre, put a less traditional spin on ballet. The classes take an athletic approach to the dance, incorporating ballet, pilates and music into an one hour session.Pure Barre teachers especially target the thighs, glutes and abs, with the idea that small movements can create big results."For example, in the thigh section of a class, you'll get into the proper position, and the teacher will guide you through a two-to-three minute exercise where you're only moving your body a couple inches," said Jorgensen. "It's tiny movements, but you'll definitely feel the burn in your thighs."Jorgensen should know the fitness benefits of dance - she's been dancing since she was three and has a degree in ballet. She also points out that a relaxed environment and enjoyable music are key components to a good dance workout."One thing that drives our classes is the music," she said. "We use variety of music, including a lot of dance mix stuff and pop music. Nothing can motivate a human body exercising like music does."