Next, extend both arms out to the sides at shoulder height, palms still facing down (as shown in photo B ). Return your arms to the curl position and then lower weights to the floor and return to start. Arm toner #7: kneeling plank ups Targets: triceps, abs Repetitions: 15 This exercise is an effective alternative to the sometimes wrist-straining tricep dips exercise - and you won't need any extra weight to challenge your arms with this move. Begin kneeling on all fours on the ground. Position your hands directly under your shoulders, and bring your knees together under your hips (as shown in photo A) . Next, bend both elbows and lower them to the floor, keeping your abs braced in tight and your back straight (as shown in photo B) . Press your body back up to your start position. Be careful not to rock your weight forward and back during the movement -- lower your body straight and down and up for maximum triceps toning.