Following her engagement to Russell Brand and rumoured pregnancy, it's no wonder Katy Perry is able to smile at the moment.

The singer looked radiant as she left a gym in Los Angeles yesterday following a high-energy workout.

Wearing a 'Be Afraid' t-shirt and knee-length leggings, Katy aimed a big grin at photographers trying to snap a shot of her engagement ring.

Katy Perry was all smiles as she hit the gym in LA wearing 'Be Afraid' t-shirt.

The singer and Russell arrived in Los Angeles from London on Sunday night after returning from their festive break in India and Thailand.

Despite only being in the UK capital for 48 hours, the pair managed to spark rumours they were expecting their first child after visiting a children's shop.

Katy and Russell - The Love Story in Pictures