This four-week workout and diet program was created by Jaclyn Sklaver, sports nutritionist and head coach for the bikini competition team FitmissNYC. “It’s important to target different abdominal muscles so you can create symmetry, while giving your body stability and the ability to perform functional movements in and out of the gym,” says Sklaver. Do your regular full-body or split routine four days a week, adding one exercise each from the abdominis- and oblique-focused groupings. Do steady-state cardio or intervals for 30 minutes, three to five days a week. Try the Bikini Abs Workout Program and the The Bikini Abs Diet Plan to tone your core for summer.