ROCKWELL — Joan Beaver’s Tuesday mornings kick off with a pool party.

During the Aqua Zumba class at the Saleeby-Fisher YMCA, she dances, sings, laughs and splashes her classmates.

“They had me at the start,” Beaver said, thinking back to her first class. “I really, really enjoy it. It makes me feel good.

“You feel invigorated when you come out of the pool, ready to start the day.”

The smile never fades from Beaver’s face during the 45-minute workout that includes moves such as kicking, twisting and shaking to classics like “Love Shack” and the latest hits, like “Gangnam Style.”

“It’s wonderful,” Beaver said. “I love music and I love dancing.”

Beaver said she started doing Zumba on land before she decided to get in the pool on a suggestion from her doctor after having a knee replacement.

“I’ve been amazed at how I’ve been able to build muscle using the resistance of the water,” she said. “I still work up sweat, but the water makes the workout refreshing.”

Instructor Debbie Hairgrove said the buoyancy of the water takes the pressure off the joints, making Aqua Zumba the ideal workout for people who have arthritis or are coming back to the gym following injury or surgery.

“People think you work harder on land, but you actually work harder in the water,” she said.”It’s a low-impact cardio exercise because you’re so much lighter.

“It’s a whole different environment.”

Hairgrove said participants also don’t see their heart rate rise to the same level it does during a typical Zumba class.

“It’s about 13 percent lower in water, according to Zumba,” she said.

Aqua Zumba helps people build strength and endurance, Hairgrove said.

“That translates to land when they leave the water,” she said. “People who haven’t been able to bike, run or attend other classes can work their way into that through Aqua Zumba.”

Hairgrove mixes up the music each week, but she said some songs are often back by popular demand.

“I try to play the music they like,” she said.

Lisa Schnuit also started with Zumba on land, but decided it was time to mix it up.

“I love the music, I love the workout, so I thought ‘Why not try it in the pool?’” she said. “I’ve really enjoyed doing it.”

Schnuit said she keeps coming back for more than the exercise.

“There is a lot of camaraderie among us,” she said. “We all have so much fun together.”

Bridget Dexter, the Y’s associate executive director and aquatic director, said the gym has started offering more water workout classes in order to provide members with options.

“Recently, we’ve started adding classes to target the younger, more fit,” she said.

Besides adding Aqua Zumba, Dexter said there is a popular Water Warriors class in which participants do a Cross Fit-type workout.

“They get out of the water to do things like laps and pushups,” she said.

During Power Hour, people do interval training in the water. Aqua Yoga offers people the chance to get stretched out. The Hydromania class is water aerobics for people at an intermediate level.

“There are so many benefits to working out in water,” Dexter said. “You are weightless, so it’s not as hard on the joints and people can still see the results.”