Celebrity personal trainer Tony Martinez is spilling the celebrity workout tea to the Daily Mail, revealing the kind of kick-ass routines he uses to get divas like Britney Spears, Pink, and Janet Jackson in the best shape of their lives.

When it comes to keeping her body snatched, Martinez says Britney's workout is all about her core.

"She loves core workouts. She's a very tenacious woman," he said. "She wants to get it done and get it done right."

The 47-year-old personal training star said that when he helped get her body right two years ago, before her Piece of Me residency kicked off in Vegas, he introduced her to core discs.

"Core discs are little circle things that I had made up for my product and we use those for a lot of ab workouts. We use those for mountain climbers, will do a barrel role tuck in where you turn around all the way over and then you bring your knees in. So really functional exercises that she likes, and she's like, 'I really feel this,'" he said.

On top of balancing out her proteins, carbs and fats through dieting, Martinez says he got to know the pop superstar well. "She's just like a regular person. Really nice, just really sweet girl," he said. "She just has a great sense of humor. She's just funny and likes to crack jokes."

On Pink's workout secrets:

I call her an athlete entertainer. She's very athletic. We would do stuff on a skateboard because she use to be a skateboarder, she loves that. She's a good athlete.

I'd also make her do fun stuff on a trampoline afterwards, then get back on the skateboard. She was on the skateboard doing lateral raises, it was amazing! I have to be creative to keep her on her toes.

On Janet's workout secrets:

I amp up a lot more cardio. We did two-a-days, cardio, and eating very, very clean. Smart nutrition is half the battle.

We pretty much just upped her protein a little bit more and gave her good carbohydrates instead of bad carbs. I gave her more whole grains, sweet potatoes, brown rice, but a lot more vegetables, and she had no problem with that, the weight just came right off of her no problem.

And Martinez's tip for everyone — even people like us? Have fun!

"I try to make [working out] fun so they don't realize that they're coin git. So basically I trick 'em. I trick 'em into having fun and it works."