Having big arm muscles can help your physique stand out in a bodybuilding contest, and turn heads in the gym. Your arms are composed of two main muscle groups -- your biceps and your triceps. In order for your arms to grow, you need to train them both equally. Getting big arms requires consistent and intense training based around 10 main exercises. Perform six or less reps for strength, six to 12 reps for hypertrophy and over 12 reps for muscular endurance.
Close Grip Bench Presses
During a bench press, two main actions occur -- Your chest muscles adduct your shoulder joint to bring your arms closer into your body, and your triceps extend and straighten your elbow. To make the bench press a more triceps-dominant exercise, move your grip in so that your hands are around 8 to 12 inches apart, and perform bench presses. This takes your chest muscles out of the movement and really focuses in your triceps.
Like close grip presses, pin presses are a variation on the traditional bench press. Set the pins in a power rack so that they are 6 inches above your chest when lying on a bench, and press the bar from there. This puts more strain on your triceps, and you can perform each repetition from a "dead-stop" on the pins, meaning that you can use more weight.
Dips were a favorite exercise of former champion bodybuilder Vince Gironda, who believed in their effectiveness at building muscle so much that he chose dip stations at the expense of bench presses in his gym. Aim to keep your torso upright when you perform dips and descend as low as you can on each rep. Once you can do 15 body weight reps, add extra weight using a weight vest or dipping belt.
You can perform pushdowns on a cable machine using a variety of different grips and attachments. Make sure you perform all your reps through a full range of motion, and use as little body momentum as possible. You can use straight handles, cambered bars, V handles and ropes as attachments, and vary your grip between underhand, overhand and neutral to keep your training interesting.
Rolling triceps extensions are often performed by powerlifters looking to increase their lockout strength in the bench press. The rolling extension is performed lying on the floor with a pair of dumbbells, and is a cross between a strict triceps extension, a chest press and a pullover.
Preacher curls focus on the long head of your biceps muscle, which is especially important for developing your biceps "peak." Preacher curls also force you to perform strict curls, which means using a lighter weight, but getting a great muscle contraction.
Concentration curls were a much-used exercise of Arnold Schwarzenegger during his bodybuilding career, as he believed that like preacher curls, they helped to emphasize the biceps peak. Do your concentration curls with your working arm resting against your knee, starting with your arm completely straight, and finishing with the dumbbell lightly touching your chest.
While often thought of as a back exercise, chinups are also great at packing mass on your arms. To focus more on your biceps, do your chinups with a close grip, and your hands in an underhand or neutral position. As with dips, if bodyweight chinups are too easy for you, add weight to make them harder.
Thick Grip Curls
Doing any of your curling or pulling exercises with thick grip dumbbells or barbells forces your forearm and biceps muscles to work harder, which leads to increased muscle growth. If you don't have access to thick handled bars, then purchase some thick grip attachments, or wrap a towel around the handle when performing curls.
Incline Dumbbell Curls
Incline dumbbell curls are much like regular seated dumbbell curls, but you perform them sitting on an incline bench, set back to around 45 degrees. This enables you to get a much bigger stretch in your biceps when in the bottom position of the exercise, and also means that you can't use any body momentum to "cheat curl" the weight up.