There was always tension between the feistiest Spices - and it looks like the boxing gloves are back on, literally, for Geri and Mel B.

While both try and kick off proper careers stateside, Star Style can reveal that Geri's desperately jealous of Mel's newfound success - and has cranked up her workout regime to show Hollywood just which one of the girls deserves to be the spice of Hollywood life.

Mel B
It's hard to believe that just over a year ago, after the birth of Angel Iris, Mel weighed 73 kilos. But, thanks to a successful stint on Dancing With The Stars, which demanded five hours of gruelling practise a day and months of training in the run-up to the Spice Girls world tour, Mel's shed 16 kilos - and is now in the best shape of her life.

Hiring personal trainer Joey Kormier the moment she got back to LA after the tour, Mel's been working to maintain her new physique - snaring a lucrative underwear modelling contract with Ultimo in the process. Add that to her own TV show and a soon-to-be-released workout DVD, and it seems Mel's new buff body really could help her reach A-list star status once again.

The exercise regime:
While dance practise is no longer a part of Mel's daily routine, she fits in plenty of other exercise to stay in fashion shoot shape.

Working out every other day, Mel interchanges power walking and yoga with swimming and Brazilian dance-based martial art, Capoiera. Add that to weight training and gym-based cardio, and it's no wonder Mel's looks her best ever.

Geri
Unsurprisingly, Geri's competitive streak became more than apparent when the Spices announced they were getting back together. But since discovering how in-demand Mel B has become within showbiz circles, Geri feels overshadowed by her increasingly successful bandmate, and is doing anything she can to get back in the limelight.

Despite finishing the world tour back in January, Geri's continued to train like a demon, and is determined to be the tiniest, most toned and most celebrated of the Spice Girls. And while Geri's super-fit new body may have snared her a new man (dancer Ivan ‘Flipz' Velez), the diminutive star's exercise regime has left her far-from-unfit fella wishing someone would hide his trainers.

"He says her house is like a boot camp," revealed a source. "Geri has been involving him in stretching sessions after her rigorous routines and has made him go on long bike rides and early-morning runs."

The exercise regime:
Well known for her obsessive exercise regimes, 35-year-old Geri maintains her size six frame with a gruelling daily schedule.

Working out for at least two hours every day, she combines running and cycling sessions with yoga, and trains with kettlebells, which work far more muscle groups than most other exercises, and can burn up to 1,500 calories an hour. But despite Geri's absolute dedication to making her body a Hollywood hot ticket, will it be enough to knock Mel off her-star studded perch?