After going through a rough depression stage, Rob Kardashian has finally decided to take action to lose the pounds that he gained.

According to Fashion & Style, the Kardashian sisters' only brother is very active and visible in the gym. His trainer, Gunnar Peterson, revealed that the reality star is very dedicated in his workouts and training.

"Rob's a grinder, he's getting it done. He's one of those guys who is always going to keep at it. He'll get to where he needs to be and everybody has their path," shared Peterson.

Rob's workouts, according to Peterson, consist of intervals and strength movements. He also revealed that the star is making progress in his training.

"It's about getting his heart rate up and keeping it up," said Peterson, adding, "I don't have a scale, I'm not big on measurements. Until a person looks in the mirror and is happy with themselves, you have not reached your fitness goals."

"People forget he's on the show, he has a sock business and he has other interests. He'll start seeing it and feeling it in a couple of weeks and will see major changes in six to eight weeks," the trainer parted.

Meanwhile, E! News reported that Kardashian matriarch Kris Jenner spoke about how Rob and all of her daughters went through a "chubby" stage when they were still kids.

"Everybody went through it. They had braces, they were awkward. Rob was chubby and that's when kids need you the most," revealed Kris, saying that it was during that time that she taught and gave her children a sense of self-esteem to help them fight off the jibes they received.

The mother/manager also shared about the support that her children are providing for each other, especially with Rob who is going through a difficult time.

"We're such a close family, that we're always encouraging one another. Because you do get a lot of criticism when you're in the public eye-constantly-whether you want it or not," explained Kris.