Michelle Obama put through her paces with Desmond Tutu

Michelle Obama was not afraid to work up a little sweat yesterday when she did some press ups with Archbishop Desmond Tutu.

There was not a bingo wing in sight as the first lady and Tutu got together with youths for some keep-fit during a visit to the Cape Town Stadium.

Tutu may be going on 80 but he showed he was as fit as ever as he joined in the push-ups and dribbled a football around the sports hall.

He said the first lady was a VIP but added to the youngsters present that they were all VSPs – "very special persons".

Mrs Obama added: "In order to be a VSP, you've got to be what? A VHP – a 'very healthy person'. Right?

"Which means you've got to have the knowledge and the internal wisdom to make sure you're taking care of yourself.

"It's hard to have an impact if you're not in the best condition possible."

She later went to the University of Cape Town where she met a group of children and admitted that her favorite food was French fries.

"I can't stop eating them. But eat your vegetables. And exercise," she told them.

The first lady was in South Africa this week on an official solo visit. She had been due to visit the prison cell on Robben Island where former President Nelson Mandela was incarcerated but the trip had to be cancelled due to bad weather.

She met Mandela briefly at his home earlier in the week.

After concluding her visit to South Africa yesterday, the first lady is heading to Botswana.