With the smell of chlorine permeating the air, a colorful beach ball is batted back and forth across a net to the sounds of screams and laughter.

This is water volleyball.

"It's a lot of fun. We laugh more than we do anything else," said Alan Chance, a retired Chattanooga police officer. Mr. Chance said water volleyball is a good way to get in some cardiovascular exercise without too much wear and tear on his joints.

"(Water activity) is great for the joints because they have that resistance," said Frances Archer, director of aquatics at the downtown Sports Barn, where a mix of regulars and newcomers gather to play water volleyball every Monday and Thursday evening. "(The participants) get a lot more activity and exercise than it looks like. They have to move through the water to get to the ball, which really requires a lot of strength."

Judy Alleen, 71, has found the activity so beneficial, she's encouraged others to join. Water volleyball, she said, has helped alleviate symptoms of arthritis to the point that "I don't really take meds anymore." In fact, Ms. Alleen said she would probably only be inclined to miss the twice-weekly game if she were in the hospital.

Anna Protano-Biggs attends with her fiancé, Jeremy Belk. She said the warm water helps with her joint troubles, and she appreciates the toning benefits from water resistance, as well as the cardio workout.

"You wouldn't think it is," she said, "but we move around like crazy. It gets competitive, so we work up quite a sweat."

Rachel Burson, 17, said water volleyball and Wii Fit are her primary forms of exercise, and she is reaping the benefits.

"My calves seem to be more athletic-looking and sculpted," she said, "and I'm a bit stronger in the abdomen."

Socially, she described it as a "chillax" atmosphere. "The people are really nice, good and friendly," said Rachel, who is separated from most of the other players by a generation, at least. She and her father, Barry Burson, play water volleyball together.

"It's a blast and a stress reliever," said Judy Jasinski, 55. "This just makes my week even out.

Tom Davish said he comes to water volleyball to lose weight and maintain mental health.

"(My doctor) said the best thing for your brain is exercise, so I exercise a lot."

Mr. Davish, 81, has lost 10 pounds in the last month, he said, and has enjoyed the process of doing so.

Since her church changed visitation to Monday nights, Ms. Alleen has missed it in favor of water volleyball.

She worries a bit that her pastor would prefer she be at church but subscribes to the theory that the body is a temple.

"I think it's that important," she said. "People should place importance on physical exercise of the body."

In fact, when a woman at church requested prayer for back pain, Ms. Alleen had a better idea.

"You need to get into a water exercise program," she told her fellow congregant. "I promise you, it will help."