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.

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.

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 ...

When most people think of core exercises, they think crunches and sit-ups – possibly because the tactical professions have used them for decades. But given recent changes in military testing, the next ...