Are you looking to kick off a new fitness routine or simply make yours a little better? Our 60 Seconds To Fit video series is here to help. "Each exercise targets multiple muscle groups," says celeb trainer Sadie Kurzban. This short clip breaks down exactly how to do the hand-weighted criss cross. This move builds stronger arms and shoulders. Using dumbbells, you'll alternate crossing your hands in front of you and lifting the weights to your shoulders. Don't forget to engage your core to get the most out of this exercise.