Believe it or not, six-pack abs aren't a dead giveaway that you've got a super-strong core. “The truth is, if you get lean enough you will have a great-looking midsection,” says Matthew Uohara, ...

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.

As a runner, you don’t want to neglect core strength. These key midsection muscles provide the stabilization and upright posture you need to run efficiently and injury-free. And you can really turn up ...