"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." All it takes is a tweak or two, and virtually any exercise for any muscle group can instantly become a ...

Core exercises for stronger abs include crunches, teasers, planks, and body-weight squats. A strong core helps improve balance and posture.

Sit-ups and crunches both target your core muscles, but work differently. You can use both exercises to build strength, endurance, and control.

When most people think of a strong core or achieving abs, the first exercise that comes to mind is often sit-ups. While sit-ups have long been a go-to for strengthening the core, they're not always ...