'Dancing With the Stars' Contestant Robert Herjavec Talks Training, 'Shark Tank'

Robert Herjavec has always been compassionate toward the entrepreneurs who appear on "Shark Tank."

However, since he joined "Dancing with the Stars," his respect for them has grown.

"I'll have a greater appreciation for how people feel when they come out in front of us. I was probably the most empathetic one to begin with, but I'm gonna be in front of many, many millions of people, live, being judged by someone else and that's a unique feeling for me," he told ABC News. "I understand how people feel and how much work goes into going out there."

He's certainly put the work in himself. Since he began prepping for ABC dancing series a few weeks ago, Herjavec said he's already seen changes in his body.

"I’m at the gym the other day and I’m looking at the mirror and I see myself and I’m like 'Wow, what a great butt. ... Oh! That’s me!'" he said with a laugh. "It’s amazing. I didn't know that people had this many muscles, and every one of them is sore."

Paired with Kym Johnson ("She's an angel because she puts up with me!" he gushed), Herjavec explained that now, his days start at 5 a.m. Because so much of his business is based on the East coast, he catches up on email and works for three or four hours and then heads to the gym to meet Johnson. After several hours (and sometimes, several injuries), Herjavec goes back to work. He passes out at midnight or 1 a.m.

"I keep forgetting to eat, I'm so focused!" he said with a laugh. "But sharks never sleep."