Ciara on How She Lost 60 Pounds in 4 Months After Giving Birth

On how she stays in fighting shape: "Five days a week, Gunnar puts me through an hour-long plyometric cardio circuit that always includes boxing elements. What's amazing is that you're getting three-in-one training: it's hitting your muscles; it's a cardiovascular workout; and it's a mental exercise . . . After I've done a few rounds, I feel as if I can conquer the world."