Secret behind Michelle Obama's arms finally revealed

Michelle Obama's longtime trainer is breaking his silence, spilling the workout secrets that keep the First Lady fit for her favorite sleeveless outfits.

Michelle Obama

"She's truly committed herself to the importance of health and fitness," Cornell McClellan tells Women's Health magazine.

McClellan, who began training Obama in 1997, said her sculpted arms are mostly the result of tricep pushdowns and hammer curls.

The trainer, who owns the Naturally Fit fitness center in Chicago, reveals the First Lady usually does an intense calorie-burning cardio workout.

Using a straight bar attached to the high pulley of a cable station, she'll do as many tricep pushdowns as she can without resting. The exercise also works her now-famous deltoids.

Obama told Children's Health that she's trying to set a good example for her daughters, Sasha and Malia, by working out and keeping a healthful diet.

"We are their primary role models. And if they see me exercising and thinking about what I'm eating, if they see their father, as busy as he is, getting to the gym and playing sports, when they grow up they'll understand that this is a natural part of being an adult," Michelle Obama said.