Your triceps -- the muscles on the back of your arms -- has three heads. While all three aspects of your triceps function to extend your arm, or straighten out your elbow, the long head of your triceps crosses your shoulder joint. To fully activate the long head of your triceps, you must stretch your arm out above your head. Only when your arms are in a fully extended position and your shoulders are flexed does this aspect of your triceps get completely activated. Consult a health care practitioner before beginning any exercise program.
Sit on a heavy bench with back support. Your torso must be vertical. Plant your feet firmly on the ground.
Hold a barbell overhead with your hands 6 to 12 inches apart. Your palms should face up. Your elbows must be locked and your arms straight overhead.
Lower the barbell behind your head. Lower only to the limit of your flexibility. Return the barbell to its original position. Only your elbows should bend during this exercise. Repeat for sets of eight to 15 repetitions.