Michelle Obama cranks out 25 push-ups on 'Ellen DeGeneres Show'

"How many was that?" DeGeneres asked the audience.

"I just stopped," Obama said after the crowd yelled out a resounding number of 25 push-ups.

Obama appeared on the show, set to air Thursday, to promote her “Let’s Move!” campaign, which encourages daily exercise and good eating habits to combat childhood obesity. The first lady recently unveiled updated nutrition standards for school meals required by the 2010 school nutrition bill with the help of celebrity chef Rachael Ray and Agriculture Secretary Tom Vilsack.

Obama told DeGeneres that she is able to fit in a hour and a half work out — usually cardio activity, weight lifting and plyometric exercises — every day, usually after getting her two girls off to school.

DeGeneres then threw the gloves down, issuing her the push-up challenge.

"I can do some," she said. "I was just wondering if you could do more push-ups than I can."

Obama accepted the challenge and both women tore off their jackets and settled into push-up position. With the crowd counting along enthusiastically, the first lady seemingly effortlessly made it to 25. DeGeneres only made it to 20, lying exasperated on the floor while Obama wrapped up.

"And I thought it wouldn’t be good to show up the first lady,” quipped DeGeneres. “So, I stopped because I thought this looks bad that I’m going to beat her."