Add Yahoo as a preferred source to see more of our stories on Google. Man exercising with dumbbells. While sit-ups and crunches are an effective way to train your core, you can work your abs just as ...

As a fitness editor, I love that deep core shake you get after a minute-long plank. That said, if I’m in a busy gym, or I’m taking my workout outside now the weather is nicer, the chances are I’ll ...