This no-movement exercise is one of the most reliable ways to measure core endurance, posture control, and spinal protection—making it a favorite among U.S. fitness professionals.

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.

Standing core exercises after 55: test elite stability with 4 holds, with expert tips from a NASM-certified trainer.

Core strength is more than just achieving sculpted abs—it’s the foundation of movement, balance, and injury prevention. A weak core can lead to poor posture, chronic pain, and decreased athletic ...

Nick Blackmer is a librarian, fact-checker, and researcher with more than 20 years of experience in consumer-facing health and wellness content. Lie on the mat with your arms extended straight up.