After flashing her abs in teeny bikinis while on vacation in Hawaii, Spears returned to the stage at Planet Hollywood wearing a sporty yellow crop top and tie, green underwear that read "Kisses," fishnet stockings and thigh-high boots.
Another abtastic outfit in rotation reminds us of her "Gimme More" costume at the 2007 MTV Video Music Awards.
"I like my workouts to be effective in a short amount of time," she told the publication in 2014. "I start with 20 minutes of intense cardio -- usually running -- move on to light free weights, body-weight exercises such as push-ups, squats and sit-ups, then finish it off with a stretch."
Whatever Spears is doing, it's clearly working for her.