If you want flatter abs, a well-rounded approach works best. Tackle the problem from a number of angles, and you'll increase your odds of success:

  1. EAT LESS. Consume fewer total calories each day.
  2. STRENGTH TRAIN. Increase your metabolism through a general strength-training program. The more muscle mass you have, the more calories you burn all day long. If you're not yet following a strength training program, working with weights for just 20 minutes twice a week should be enough to start building more lean muscle.
  3. CRUNCH. Include crunches or other ab exercises as part of this strength-training program.
  4. DO CARDIO. Burn more calories through regular cardiovascular workouts, such as walking, running, cycling, skating, etc.