Fergie  fitness running scar spandex trainer sunglasses

She's workin' on her fitness!

On Sunday Fergie and her trainer went for a hike in the Hollywood Hills, and the 38-year-old singer worked up quite a sweat. Her hubby Josh Duhamel attended the G.H. Mumm Art of Celebration Formula 1 event in Austin, Texas on Saturday night, so it looks like Fergie Ferg and baby Axl Jack were on their own for most of the weekend.

But back to Fergs -- is this just a bad angle or is there something else going on?

Fergie  fitness running scar spandex trainer sunglasses