Strengthen your core after 55 with 4 chair drills that train rotation, lower abs, and anti-rotation without floor strain.

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.

Try these 6 joint-friendly standing moves to fire up your core, raise your heart rate, and help trim belly fat after 50.

Deep inside Earth is a solid metal ball that rotates independently of our spinning planet, like a top whirling around inside a bigger top, shrouded in mystery. This inner core has intrigued ...