Katie Price says one of the bonuses of having fake breasts is that she doesn't need to wear a sports bra - because they're ''stuck'' on her chest.

The 39-year-old former glamour model is set to run the London Marathon this weekend and admits she won't need extra support for her ample assets because her surgeon has ensured they are very firm and keep their shape.

Katie has had eight operations to change the size of her boobs and her bust size is currently a mammoth 32GG.

Speaking to the new issue Heat magazine - which is out now - she said: ''I don't wear a sports bra. I've got a good surgeon, so I don't need to - Dr. Plovier, Be Clinic, Brussels.

''I go riding and never wear a bra. They're stuck on my chest like you wouldn't believe.''

Katie is to undertake the gruelling 26-mile run with her friend James and they're going to be easy to spot on the route because of the unusual costumes they're planning to wear in honour of her mum Amy, who is suffering from terminal lung illness idiopathic pulmonary fibrosis.

She said: ''We're going to be dressed as a pair of lungs. My mum is very upbeat but I have seen a difference in her. There's absolutely no way I could ever not run this marathon. She'd kill me!

Whatever happens, whatever pain I'm in - it's to make my mum proud in the end.''

The 'Loose Women' panellist - who has children Harvey, 15, Junior, 12, Princess, 10, Jett, four, and Bunny, three, from a trio of relationships - hasn't been able to train very hard for the race because she's been suffering from a recurring injury, meaning her furthest practice run has been just nine miles.

However, she insists she isn't too worried that she'll run out of stamina on the big day.

She said: ''I haven't gone the distance I did before because my knees are damaged. But I'd rather save my strength for marathon day ... I'm really looking forward to it.''