Lily Allen needs heat to keep fit

Lily Allen is obsessed with exercising in a hot room.

The Fear singer attributes her new slender figure to Bikram yoga, a series of body-contorting postures performed in temperatures of 105 degrees Fahrenheit, and insists on putting herself through lengthy gruelling routines.

A source said: "She does the intense 90-minute workout twice a week. She's really pleased with her new figure and it has landed her a modelling deal with Chanel."

The 24-year-old star, who has previously branded herself "fat and ugly" was unveiled last week as the face of the fashion house's forthcoming Autumn/Winter 09 handbag advertising campaign.

The singer is said to be feeling the pressure of taking on such a high-profile campaign.

A source added to Britain's Daily Star newspaper: "Lily cannot believe her luck but she is nervous.

"Her last fashion endorsement with New Look went well but she felt under a lot of pressure competing with Kate Moss' Topshop range. Now it's even worse because this is a world-class designer label and Lily doesn't want to let anyone down.

"She is a massive Chanel fan - one of the first things she did after releasing her first album 'Alright, Still' was buy a Chanel dress costing £2,000 - so this is a big deal for her."