Fittest First Lady: Michelle Obama drops to the floor in an impressive push-up challenge

Completed 25 push-ups on Ellen DeGeneres show beating the TV host

Michelle Obama has been touring California promoting her health agenda, so when she was challenged to a push-up contest on a TV show, she quickly dropped to the floor to prove she practiced what she preached.

The challenge began when daytime TV host Ellen DeGeneres asked the U.S First Lady on her show: 'How many push-ups can you do? Because I like to do a push-up.' 

'I don't know I can do some - can you? I know you've got these back issues,' Mrs Obama teased.

To which the TV host stood up and took off her jacket, and a smiling Mrs Obama, who has completed push-ups with Archbishop Desmond Tutu stood up ready to take on the challenge.

The pair started doing the push-ups on the studio floor with the audience counting along - Mrs Obama completed an impressive 25. 

'I thought it wouldn't be good to show off the first lady so I stopped,' quipped DeGeneres after quitting. '

I thought this looks bad that I'm going to beat her. I'm 54 and you're 48.'

During the show, Mrs Obama also revealed some bedroom secrets regarding husband Barack.

He doesn't pick up his socks.

'He thinks he's neat but he has people who help him. I'm like it's not you that's neat. It's the people who pick up your socks. Those are the neat people,' she told DeGeneres. 

She also joined host the TV host in a boogie for the benefit of the audience.

Healthy laughs: Mrs Obama cajoled Jay Leno into trying out some apples and sweet potato fries after the host said he hadn't eaten a vegetable since 1969

The First Lady has spent the last few days in California, promoting her health agenda and making high-profile TV appearances.

On Tuesday night she  told Jay Leno 'I can't sing' on Tuesday night, but claimed that her husband was in the habit of serenading her.

Earlier on Wednesday Mrs Obama spoke in a vacant store in Inglewood which is set to refurbished as a health food store.

She praised efforts to improve public health, saying: 'We're not just making this generation healthy. We're making the next, and the next and the next.'

The day before, she revealed that the President loves to serenade her by singing songs from Al Green, Marvin Gaye and other R&B greats. 

'He does have a beautiful voice, and he sings to me all the time,' Mrs Obama told Mr Leno on The Tonight Show.

The President gained attention in January for breaking out a bar of an Al Green song during a fundraiser at the Apollo Theater in New York City. 

But he also sings Marvin Gaye and even 'a little Stevie.' That's Stevie Wonder, for the uninitiated. 

'He likes the classics,' she explained. 

However, her appraisal of Republican front-runner Mitt Romney's choir voice was a little less generous. 

Mr Romney surprised supporters in Florida with an off-pitch version of 'America the Beautiful' on Monday, and Mr Leno asked the first lady for her opinion.

'It's beautiful,' she said after a pregnant pause, with a laugh and raised eyebrows.

'And it is America's song, and it's a song that's meant to be sung by every American,' the First Lady said in a taped appearance for the NBC show.

Mr Leno told her, 'That is right, regardless of political affiliation.'

Michelle Obama also cajoled Mr Leno into nibbling on apples, sweet potato fries and a pizza made with eggplant, green peppers and zucchini, breaking his long-held aversion for all-things-healthy in his diet.

Mr Leno once told a magazine he hadn't eaten a vegetable since 1969, and he insisted he tasted his last apple in 1984. That didn't dissuade the First Lady, who's promoting her 'Let's Move!' campaign to get kids excited about fitness and healthy eating habits.

Earlier, Mrs Obama poked at him in a Twitter post, hinting she'd 'get Jay to eat some veggies' on the NBC show. He did.

'That does smell very good. I assume this is sausage-pepperoni,' the comedian quipped as he eyed the pizza made with a whole-wheat crust.

She convinced Mr Leno to dip an apple in honey made from beehives in the White House garden: 'It will help it go down easier,' she assured him.

'White House honey? That sounds bad,' MrLeno told her. 'You know, with a different president that could mean a whole different thing, "a little White House honey.'