These 5 chair moves target lower abs and obliques to help tighten your midsection and improve posture after 50.

This 10-minute morning circuit activates deep core and glutes to help tighten your waist after 50, no gym required.

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.