At first glance, the health-conscious London Bridge singer appears as lean as usual in photographs of her out jogging in Los Angeles.
But a closer look reveals Fergie suffers from that skin scourge dreaded by millions of women - cellulite.
Cellulite strikes super-fit Fergie, out for a run in Los Angeles
However, the 33-year-old - real name Stacey Ferguson - is unlikely to worry too much about an unflattering photo.
As a solo artist and the frontwoman of the mega-selling Black Eyed Peas, she's also expected to marry her boyfriend, Transformers star Josh Duhamel, who she's been dating since 2004, later this year.
Just last month, former crystal methamphetamine addict Fergie proved her stunningly high level of fitness during a performance on U.S. TV's Today programme.
Former drug addict Fergie leads a healthy lifestyle with her fiance, actor Josh Duhamel
During a rendition of the Heart song 'Barracuda' , she adeptly turned her body 180 degrees in the air and positioned one hand on the ground to carry her full body weight, while her other hand was clutched on to her microphone.
Fergie then wowed television viewers with three more one-armed cartwheels.