Jay-Z has revealed US President Barack Obama exercises to his music.

The '99 Problems' rapper has revealed the political leader is a big hip-hop fan and uses his expletive-riddled tracks to inspire him during his work-outs.

Jay-Z said: "Barack loves hip-hop. When I called him he was playing my 'Blueprint' album in the gym.

"I've been invited to the White House a couple of times. Hopefully, we'll keep him for eight years so I'll have time to get there."

Jay-Z - who is married to Beyonce Knowles - recently threw a lavish 40th birthday party in the Dominican Republic and admits the best thing about the bash was outdoing his friend P. Diddy, who is famed for his extravagant celebrations.

He added to UK TV talk show host Jonathan Ross: "Puff throws the best parties ever but I got him this time. He practically MC'd my party."

The music mogul - who has his own Roc Nation music company and was previously president of Def Jam records - recently advised record companies to become "smarter" in order to survive.

He said: "People have to be smarter about how they A+R, and what they put out, record companies need to catch up to that, someone needs to send them the memo.

"I remember the first year I was at Def Jam we put out 56 artists. There isn't 56 great artists in the world, and this is one company. One company operating for around 80 artists in a year. That's just too many."