It has been a circus prop, a toy and a 1950s fad, and now the hula hoop is making a comeback as a workout tool that fitness experts say provides an effective cardio and even meditative workout.

A new generation of hoop activists is putting another spin on the hoop, which ancient Greeks fashioned from grapevines and used to exercise the hips.

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Circus hooper Marawa Ibrahim, known professionally as Marawa the Amazing, lives a nomad’s life performing and teaching hula hooping around the world.

“Fitness hooping is what I’m really into. Even at circus school I developed a workout using core muscles to push the hoop,” said Ibrahim, who can spin 133 hoops simultaneously and has appeared on the UK reality show "Britain’s Got Talent."

The 32-year-old Australian said anyone, regardless of age or fitness level, can keep the hoop spinning but choosing the right size hoop is essential.

“You can’t hoop with a kid’s hoop. When you were a kid you were half as tall,” she said, adding that a hoop should reach to the hips, at least. “I used to teach a gym class of overweight women. I made hoops that were almost up to their armpits and they could do it.”

Proper technique also means balance. Even the pros can develop lopsidedness, she said, so spin in both directions in order to tone the body evenly, head to toe.

Kelly Strycker is the director of Chicago Hoop Dance, a community-based collection of performers, teachers and students who practice hooping as a form of moving meditation similar to Yoga, or Chi-gong, the Chinese system of exercise and breath control.

“There definitely is a circus overlay in hoop dance,” said Strycker, adding toned muscles and weight loss are common benefits. “It tends to be a fitness workout because of the nature of the movement.”

Strycker said hoop dancing, which includes elements of yoga, attracts mainly women between 25 and 60 who want a fitness routine they will do.

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Her classes, held at venues including parks and beaches around Chicago, include 20 to 25 minutes of yoga moves, lunges and squats, and hooping for the wrists, hands, shoulders, legs, hips and waists.

“The meditative aspect is in the rhythm, the rocking movement that stimulates the heartbeat, the back and forth,” she said.

Dr. Cedric X. Bryant, chief science officer at the American Council on Exercise (ACE), said a 2011 ACE-sponsored study found that hooping could burn up to 600 calories an hour.

"We found that just by the nature of movement it did a pretty effective job,” Bryant said. “The only downside is if one had difficulty mastering movement. But larger hoops reduce the learning curve.”

Ibrahim said a hoop, unlike a trapeze, is portable and fun.

“Walk up to any kid and they’ll have a go at it,” she said. “Everyone’s happy."