You might take you a week or two to get into the habit of knocking out weighted crunches, but the pay off is a time-effective way to level-up your abs. We think you’ll love this method.

How to Do It: Grab a pair of light to moderate weight dumbbells (you should have no problem curling for reps). Perform 10 biceps curls. Rest for 10 seconds. Immediately proceed into a second set of 10 ...