Rob Kardashian’s trainer hits back at the critics: 'He will get back to his best shape ever'

He’s the celebrity trainer behind some of the hottest bodies in Hollywood, with Gunnar Peterson now turning his attention to Rob Kardashian.

A hard job? You bet. But Gunnar isn’t quitting despite the waves of criticism hitting Rob, 27, and his struggle to shift the pounds.

Speaking to E!, the trainer says: "He's such a good guy. Rob was a solid basketball player, a serious runner and he's a serious athlete. It's when life gets in the way, that's what makes it hard to get to the gym."

So, what’s been the problem? Gunnar says that Rob’s endless job commitments are a massive issue for his work-out schedule.

He adds: "He's pitching shows, he's on a show, he has his sock line and other business ventures."

Tee hee hee, a sock line.

Anyway, Gunnar says the hate Rob is receiving just “kills me” and he wants to prove those critics wrong.

He adds: "There's no doubt in my mind. With 26 years of training experience of doing this, I can tell you without hesitation that Rob Kardashian will get back to his best shape ever."

Late last month, Rob jetted out of Italy, missing sister Kim and Kanye’s wedding, over a fight with his family about his weight.

Sources said that Kim, 33, lashed out at Rob when he said he would not be pictured on her big day due to his weight gain.

View pics:The Kimye wedding Insta-shots!