Khloe Kardashian never misses a gym session.

The 'Keeping up with the Kardashians' star has lost 35lbs and been vocal about how hard she has worked to keep her curvaceous body in shape and her personal trainer of three years, Gunnar Peterson, says it's because the 31 year old is ''in love with fitness''.

He said:''Khloé gives as much to the gym as the gym gives to her. She never cancels, it can be a night where she's short on sleep. It can be a day where she has an engagement for that day. She may have something at 8 - then we're going at 6.

''There is no typical routine ... Some days it's more heart-rate intensive, some days it's more lower-extremities intensive, some days the upper extremities get a little extra love.''

Meanwhile Khloe is just as dedicated to improving her diet so that she gets the best results from the intense fitness regime.

Gunnar told PEOPLE: ''As the changes have come, the diet has tightened up ... She's made better choices when she eats. She's been more conscious about working on sleep habits. She hydrates better.

''She keeps getting after it and she keeps getting better. We're always playing with (our workouts); we're always making it that much more challenging.''