Fitness expert Charles Harris and his daughter Charli join Jenyne to demonstrate some simple core exercises to help build strength.

Zumba Fitness Core is an energized dance-fitness party game featuring choreography specifically designed to deliver tight and toned abs as well as an effective total-body workout.

Core training has always been part of military PT and fitness testing. From crunches to sit-ups, flutter kicks, leg tucks and plank poses, the U.S. military uses many exercises to test core strength.