London, July 9 :  Singer Miley Cyrus has left critics worrying about shrinking waistline but her pilates instructor Mari Winsor says there's no cause for concern.

"I think people need to chill out. She's healthy and she feels good, that's the main thing. She's smart about her body. She wanted to sculpt her body, that's all," people.com quoted Winsor as saying.

To get her toned physique, the 19-year-old has also been following a gluten-free diet and going to Winsor's classes almost daily for one-hour sessions of circuit pilates, which includes work on the reformer, mat exercises and stretching.

"What we focus on with Miley is posture. That was my main concern when she first came to me.

"I wanted to get her shoulders down and get her to relax her upper body. If you notice, her posture is a lot better. She works hard. She's focused," he said.

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