The Beach Body Workout

Credit: Laura Doss

No more excuses

The next step is finding the right workout—and here it is. "This high-tempo, no-equipment workout is designed to be done anywhere, anytime," Castronuova says. "It focuses on large-muscle groups, because the bigger the muscle, the more calories required to exercise it." Add some intense fat-blasting cardio, and together, she says, "the whole routine will help turn your body into a fat-burning furnace."

To not just tone but also lose up to 12 pounds this month, follow her diet guidelines. Carve out tiny chunks of time daily to visualize the new you. "Picture yourself as healthy, fit, and strong, and it will happen," Castronuova says.

Next: Here's the plan