Popsugar Health & Fitness Arm Exercises Best Arm Exercises If Today Is Arm Day, Here Are 59 of the Most Effective Moves You Can Do 21 March 2018 by Jenny Sugar View On One Page Photo 40 of 59 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 40 Side Plank Crunch Begin in a side elbow plank with your left forearm on the floor and your right hand behind your head. Keeping your torso stable and your waist lifted, bring your right knee up toward your shoulder to lightly tap your right elbow. Lengthen your right leg back to the starting position to complete one rep. Previous Next Start Slideshow Arm ExercisesStrength TrainingWorkouts