That voice, those hips, that booty! “I always say, ‘I don’t want to lose my curves,’” Beyoncé told Allure magazine. But while keeping her curves, she's also focused on staying toned and keeping her abs tight. “You can never do too many squats or lunges,” she insists. Take a page from the singer's book and target your middle by engaging your core with crunches on the bosu ball (which looks like a halved exercise ball on a platform) followed up by weighted lunges. You'll be bootylicious in no time!