Certified personal trainer to the stars Peter Lee Thomas is credited for getting Halle Berry in tip-top shape for her role as an assassin and he shares with The Doctors how they did it. Peter explains there is a certain mindset needed to try and modify the body to withstand the type of choreography for the action role Halle took on. They trained five to six days per week and it required hard work and disciple. Peter says he is so proud of Halle because, at 51 years old, she is doing all her own stunts!

Watch: Simone De La Rue's Best At-Home Workout Tips

ER physician Dr. Travis Stork points out that personal training has evolved to now often focus on functional moves. Peter agrees, saying, “It’s the way nature intended for us to move.” Audience member Mary Margaret volunteers to try out several of Peter’s abdominal exercises which require no fancy equipment, but rather, are all done with a one-gallon jug of water. Peter says he was inspired by working with Navy SEALs.

Just starting out? Try these moves without the water first. 

Dr. Travis asks Peter for one eating trick that he uses since Peter’s abs, which “leave people speechless” according to OB/GYN Dr. Nita Landry, are obviously tied to clean eating. Peter believes intermittent fasting is one of the best ways to reset your system every day. Peter eats all of his meals in an eight-hour window, either between 12 PM and 8 PM or 2 PM and 10 PM. Peter says, this way when he sleeps there is plenty of fasting time. Dr. Travis jokes that sadly, those abs do not come from donuts or French fries!

Watch: Workout That Targets Belly Fat?

Check out Peter’s moves in the video below and if you’re just starting a workout program, go at your own pace and check with your doctor to make sure the workout is right for you!