In this video tutorial, viewers learn how to do a core-blasting workout without sit-ups or crunches. Users will only need a timer. This workout contains 6 exercises. The exercises are: right knee-to-elbow plank, left knee-to-elbow plank, right side plank twist, left side plank twist, sit through and X-up. Do 30 seconds for each exercise with no rest in between the exercises. When finished, take a 30-60 second rest and then repeat the workout 2-3 more times for a full 9 minute workout. This video will benefit those viewers who are interested in health and fitness, and would like to lean a workout that will help them build abdominal muscles.