Greta Lee "had abs" for the first time in her life thanks to her intense training for her new movie Tron: Ares. The upcoming sci-fi action movie, the third in the Tron franchise, follows a highly sophisticated program named Ares as he is sent from the digital world to the real world on a dangerous mission. The Past Lives actress, who plays human Eve Kim, admitted on The Graham Norton Show that she had to get in the best shape of her life to make sure she could pull off all the action scenes and running sequences. "I had to run a lot in this movie - when you read a script and it says 'run for your life', you must get fit," she shared. "We trained with the man that trains all the actors, (he's) called Chris, and I had abs for the first time ever." Lee then jokingly expressed her disappointment that she couldn't flaunt her new fit look on-screen, adding, "What was upsetting is that none of the costumes showed them off!" Lee stars alongside Jared Leto as the titular program Ares, Jodie Turner-Smith as his second-in-command Athena, and Evan Peters as their creator Julian Dillinger. Appearing on the talk show, Turner-Smith revealed that her character's black bodysuit was so heavy she needed help to get it on. "It wasn't just a body suit, everything was practical. It was like armour and so heavy it took three people to get me dressed. It was insane," she divulged. Lee and Turner-Smith's interview airs in the U.K. on Friday night. Tron: Ares will be released in cinemas on 10 October.