Crunches have had their moment, but it's time to take your core training to the next level. Your abs aren't just show muscles ...

It might not be easy, but, according to Cardiello, having a flat stomach is “absolutely achievable over 50.” “But the approach should be smarter, more intentional and recovery-focused,” he said.

Discover 3 core stability exercises to build a stronger midsection, ditch endless crunches, and boost fitness effectively.