Kris Jenner

Kris Jenner

Kris Jenner makes business calls during her workouts.

The 58-year-old matriarch, who manages all of her children's careers, doesn't have time to take a break from her busy schedule and even does important phone calls while running on the treadmill at the gym.

Kris' personal trainer Gunnar Peterson told the MailOnline: "She's so driven. Kris comes to the gym at 6:30am and she's on the treadmill while on her cell phone, shouting down the phone about millions of dollars. She's everything to that franchise.

"People accuse her of wh**ing her kids out but she hasn't, she's helped her kids get jobs. I think she's done wonderful and it's unfair for people to criticise."

The brunette beauty recently admitted she finds it "hurtful" when her parenting skills are criticised because being a mother to her kids comes first.

She said previously: "As hurtful as it might be, no one knows what's going on. When someone starts criticising your role and your ability to be a good mum.

"I prided myself my entire life ... my most important role in my life is being a mum. There's nothing I wouldn't do for my kids."

Kris even keeps up the date with the whereabouts of Kourtney, 35, Kim, 33, Khloé, 30, Rob, 28, Kendall, 18, and Kylie, 17, with email notifications.

She said: "Sometimes I want to know where everybody is. I have a Google Alert on the kids, and I'll go, 'Wait, that's right! They're in Italy!' "