Welcome to our Flat-Belly Challenge : 21 days of workouts, belly-blasting tips, and fat-burning recipe ideas to help you feel slimmer and more confident all Summer. Day 4's challenge is a metabolism-boosting workout followed by a lemony quinoa and cabbage dish that's anything but boring.Source: Thinkstock / AmmentorpDK 
Metabolism-Boosting Core Workout
This ab workout  does double-duty in the flat-belly department: not only does it target your core to help define ab muscles, but it also builds muscles all over your body, which helps rev up your metabolism to burn more calories throughout the day. Get the workout below and print it out here .
Quinoa Cabbage SaladPhoto: Leta Shy
Don't be put off by the "salad" description; this warm, wilted cabbage and quinoa dish makes a light, comforting dinner that soothes tummy issues. Each ingredient helps digestion, and the fiber in the chickpeas, cabbage, and quinoa will help you debloat. If you'd like, add a dollop of Greek yogurt for a creamy element and a dose of belly-helping probiotics. Get the recipe for lemony quinoa cabbage here .