New look for Geri

She has become as famous for her yo-yo dieting as she is for her career. As a Spice Girl Geri Halliwell endured taunts for being the chubbiest girl in the band. She responded by becoming dangerously thin on a diet of yoga - and not much else.

Then, in the past year, she piled on the pounds again.

Now, in the latest chapter in the saga of her weight, it would seem Miss Halliwell is determined to get back in shape.

The star, who hopes to relaunch her music career later this summer, has signed up for a rigorous daily training regime to achieve a trimmer figure.

She looked distinctly uncomfortable as she attempted to power walk with her personal trainer near her west London home. Passers-by saw her gulping water from a bottle as she struggled to keep up with her coach. The previous day, Geri broke into a sweat during a routine warmup in Hyde Park.

Miss Halliwell, 31, has been advised to get fitter by record label bosses as she readies herself for a promotional drive to launch her first album and single in three years.

Her fitness programme combines running, circuit training, gym sessions and modern dance classes to increase her stamina and improve her physique. According to her spokesman, she now runs three miles five times a week - wearing a small backpack full of weights. She also goes to a gym near her Notting Hill home four times a week, does yoga every day and goes to modern dance classes every other day.

A friend said: "There have been numerous diets over the years, which have been well-publicised, but Geri is now just eating healthily. She eats what she likes and just has sensible portions. She isn't on the Atkins, the South Beach Diet or Blood Group Diet - she's dumped fad diets for good and is a lot happier for it."

In her days as a Spice Girl she was famously photographed bursting out of a Union Jack minidress. But after leaving the band she reshaped her career and figure. By 2001, she was said to have weighed a mere seven stone and was painfully thin. But she has been open about her eating problems, which have included a battle with bulimia that she blamed on being in the girl band.

She said: "I went into the Spice Girls, and I was one of the curvy ones. Living with other girls you are going to compare a bit. When you are in your disease it's very sneaky.

"I didn't want to share that I was going back to my hotel room and bingeing on cakes. It wasn't something I was very proud of."

Geri will make her first public appearance in months on Sunday when she hosts Party In The Park in Hyde Park alongside Duncan James from Blue. Lenny Kravitz, Avril Lavigne, Will Young, Busted, The Corrs and others will perform on the day.