(Cover) - EN Showbiz - Kim Kardashian is "poker faced" about perfecting her body in time for her wedding.

The newly-engaged reality star plans to marry professional basketball player Kris Humphries, 26, this summer. Kris proposed with a 20.5 carat custom-designed ring last month after dating the raven-haired beauty for six months.

Kim's trainer, Gunnar Peterson, has revealed that the stunning star is serious about getting her body into amazing shape ahead of her big day.

"Kim's all business when she's working out," he told Life & Style. "She doesn't do a lot of grunting. She has a poker face; she's focused."

The star, who is renowned for her gorgeous curves, has been visiting workout destination Barry's Bootcamp more than usual. The intense workouts are known for their fast pace and are useful for getting toned quickly. Kim has called the classes "torture but amazing".

The television personality has even roped her fianc into the grueling workouts. A representative from the gym has revealed that the sports star has even found it difficult keeping up with his determined partner.

"Kim even brought Kris to a class last week and he seemed pretty challenged with the workout," he said.

Kim, 30, recently drew up a pre-nup agreement ahead of her wedding to protect her Beverly Hills home and assets. (C) Cover Media