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.

Depending on your fitness level, you can use this to get started or give yourself an easy day. This workout gets the heart pumping and works the entire core system (from hips to shoulders), which is ...