Besides Alt, veteran cover girls Christie Brinkley, Tyra Banks and Heidi Klum have supported the challenge by reposting their fans' submissions.
Alt insisted it has been her secret to helping her combat the private woes she endured behind the camera.
Alt's eye-catching snap was appreciated by her followers and famous friends.
But Carol did say that if a model just wants to work nonstop and that is her goal, she should go for it.