The triceps brachii, or triceps muscle, is the large muscle on the back of the human upper arm. Located between the rear shoulder and the elbow, this muscle makes up more than two-thirds of the arm's muscle mass. The triceps is an antagonist muscle — or oppositional — of the better-known biceps. Triceps works, or underarm exercises, are classified as isolated exercises or combination ones depending upon the muscle or muscle groups they target. The best underarm exercises are those an exerciser has the equipment, strength and motivation to perform.
Aging and a sedentary lifestyle combine to cause the triceps muscle to become underused and flabby, particularly in women. If a person is overweight or obese, weight loss in combination with exercise, including underarm exercises, will be necessary to see results. Persons of normal weight or those who are slightly overweight are not going to eradicate their flabby arms by dieting alone. The only way to remedy this situation is by performing underarm exercises and toning the muscle. Reading about and then choosing an exercise is a good first step, but to see results, a person must actually perform the exercise on a regular basis.
One of the best underarm exercises to isolate and firm the triceps are push-backs, also known as posterior arm extensions, that are done one arm at a time. Push-backs require a weight bench and a smaller dumbbell weight, such as 5 lbs (about 2.25 kg). Standing, the individual places a bent right knee on the bench and then bends forward to place the palm of the right hand on the bench for stability. A dumbbell of lesser weight is held in the left hand with the elbow bent forward. The exerciser then slowly straightens the left arm out behind the back, keeping the arm close to the torso.
Bench dips are another type of triceps underarm exercises that also sculpt the shoulders and lower arms. An exerciser sits on the long edge of a weight bench with the legs straight and extended together resting on the heels. The heels of the palms are then placed on each side of the body with the fingers curled over the edge. The exerciser then slips her bottom off the bench and holds her body weight with arms. The body is lowered toward the floor by bending the arms and raised by straightening the arms.
Push-ups, skull-crushers — or lying triceps extensions — and standing behind-the-head arm extensions are also excellent triceps underarm exercises. They are best started when an individual has mastered the primary underarm exercises to ensure adequate strength. All triceps exercises should be performed slowly and deliberately in order to work the muscle body entirely and avoid injury.