Who said reality TV was easy? A glimpse into the rehearsals for 'Dancing with the Stars' shows pairs of dancers hard at work practicing steps for the upcoming season. Lots of sweat, lots of tripping over feet and still some time for smiles and high fives.

With less than a month until the Sept. 21 premiere, who will benefit most from the time in the studio and who has no hope no matter how many hours they spin and twirl?

When 'Dancing With the Stars' returns in the fall, 16 dancers will be competing for the Mirror Ball Trophy, the largest number ever, including Donny Osmond.

The list includes singer Mya, Aaron Carter, model Kathy Ireland, 'Entourage' star Debi Mazar and Melissa Joan Hart, best known for her roles in 'Clarissa Explains It All' and 'Sabrina the Teenage Witch.'

Others joining are former Dallas Cowboy Michael Irwin, Kelly Osbourne, UFC fighter Chuck Lidell, Natalie Coughlin, Joanna Krupa, Tom Delay, Ashley Hamilton, Mark Dacascos.

Fan favorite dancers Karina Smirnoff and Maksim Chmerkovskiy be also be returning, as well as new pro dancer Anna Demidova.