There's much interest in building big, well-muscled arms judging by the number of guys that seem to concentrate on this aspect of weight training and who tend to neglect an all-round program.
Nevertheless, here is an arm workout for building strength and muscle in the biceps and triceps of the upper arms, and the muscles of the lower arms -- the pronators and supinators -- which are often unintentionally neglected. Don't under-exercise the triceps at the back of the upper arm because they can make all the difference in building the bulky look of the arms.
How to Train the Arms
You can make an arm workout an "arms only" day where you do arms training and nothing else, or you can work it into an upper body workout with shoulders and back and chest, or you can do the full-body workout with a complete upper and lower body program.
One advantage of isolating arms in a workout is that you don't waste energy on other lifts and you can really hammer those arms.
Sets and Reps in an Isolation Arms Workout
Do 3 sets of 12 to 15 repetitions for all exercises. If this leaves you wanting more, add an extra set to each exercise.
Check the basic information if you're new to weight training.
BICEPS AND LOWER ARMS
Works the biceps by providing stability and isolating the biceps muscles. This can be done sitting, or standing while bending over.
Note the palms facing inward at the starting position and the rotation as the weight is bought up to the chest. This exercise hits the forearm muscles as well as the biceps. This is a must to include in an arm exercise program unless you target the lower arms separately.
The barbell curl hits the biceps full on. The bar fixes and concentrates the muscle contraction at the biceps. Use a standard bar or the ezy curl bar for a slightly different emphasis.
Another standard for upper arms. This time the exercise targets mostly the brachialis, or the muscles of the lower part of the upper arm, rather than the biceps.
You need a "preacher bench" or something that can substitute for one, to do this exercise.
This exercise is similar to the dumbbell rotational curl if you rotate on the way up, but it adds even more instability, which is good for hitting muscles that you don't get with a very fixed path, as in a barbell curl. It targets the biceps with work from the brachialis, and brachioradialis of the lower arm.
TRICEPS - REAR OF UPPER ARMS
If you have access to an assisted dip machine, they are good for graduated triceps work. Frowned upon by the purists, these machines can be useful for people starting out. They hit the three-pronged triceps muscle at the back of the arms.
The skullcrusher, in which a dumbbell or barbell is moved over the head while you lie on a bench, is a little more advanced. But once you get the feel of it, it works and adds variety, which is important when you're exercising regularly.
Also see this example with barbell.
This exercise uses any cable apparatus with adjustable plate weights. It works the triceps usefully, especially if you only push from the forearms parallel to the floor position instead of at full elbow flexion at the chest.
This is similar in function to the skullcrusher, except you sit on a bench or chair or stand. Sitting with your back supported helps stabilize the movement and concentrates muscle contraction in the triceps.
That's it. More than enough to build great arm muscle and strength. It doesn't have to be complicated to get good results. You can do this program as part of a full-body or upper-body workout, or on on its own.