Most celebs sign up for Dancing With the Stars with one very sparkly goal in mind: the coveted Mirrorball Trophy. However, thanks to the rigorous training involved in learning new dance routines week after week, many contestants wind up waltzing their way to major weight loss along the way. Of course, it’s not as simple as joining the show and automatically dropping pounds. These celebs put in serious time, effort, and sweat into training for those short performances you end up watching on TV. Former contestant Amy Purdy shared with the Los Angeles Times that contestants get their music on Tuesdays and then pretty much rehearse straight through until their performance on Mondays. New pro for season 29 Britt Stewart told Women’s Health that she rehearses every single day with her partner Johnny Weir. (Rest days don’t win Mirrorballs, folks.)”Everyone is dancing every day, building right up until Mondays/show days, when you arrive on the set at about 7 a.m. and you are there all day and all night,” she said. “Then last night we had dance practice after the show until midnight. Then we all start our routines for next week today. It’s exhausting, but it’s also a total blast.”With all that dancing, it’s only natural that a few pounds will drop in the process. While plenty of stars have talked about firming up during their time on DWTS, these 28 celebrities saw major changes in their bodies during their time competing on the show. From Lauren Alaina losing 25 pounds to Kirstie Alley losing a whopping 100 pounds, the fitness gains and weight loss goals achieved on Dancing with the Stars are nothing short of impressive.