Are Biceps Curls Compound or Isolation Exercises?

Your biceps consists of a pair of muscles that crosses two joints, the shoulder and elbow. This muscle pair is primarily responsible for helping you bend your elbow. The biceps curl is a weight lifting exercise that involves flexing your elbow to activate and strengthen your upper arm. Because the curl involves only one joint, it’s considered an isolation exercise.

  1. Compound Versus Isolation

    • A compound exercise involves two or more joints, such as a chest press in which you use both shoulders and elbows to complete the range of motion or the squat which requires movement in both your hips and knees. By comparison, when you perform an isolation exercise, you need to move only one joint throughout the exercise. In a biceps curl, the elbow flexes while your shoulders remain still. Another example of an isolation exercise is a lateral raise, in which your shoulders work while your elbows remain stationary. Because compound exercises engage more muscles, your body produces more human growth hormone, which results in greater muscle growth.

    Proper Execution

    • When you perform a biceps curl, you can use a barbell, dumbbells or gallon jugs filled with water. To perform a standard biceps curl with a barbell, stand with feet shoulder-width apart while holding the bar with a shoulder-width grip, with your palms facing forward. Fully extend your arms down toward the floor. Support your core and slightly bend your knees. Keeping your elbows tucked by your sides, exhale and curl the barbell toward your chest. Inhale and slowly lower the weight back to starting position. Perform six to10 reps for one to three sets. If you want to put more stress on the outer head of your biceps, perform the curls with a closer grip to slightly rotate your arms out. A wider than shoulder-width grip emphasizes the inner head by slightly rotating your arms inward.

    Types of Curls

    • The various types of curls – preacher, barbell and concentration -- put pressure on your biceps during the different phases of a curl’s range of motion, according to “Optimal Muscle Training” by Ken Kinakin. For example, a preacher curl, where you sit on a preacher bench with your arms fully extended onto the pad to support your elbows, emphasizes the first phase of elbow flexion. The standing barbell curl puts more pressure on your biceps during the middle phase of the curl’s range of movement. When you’re sitting on a bench and bracing your working arm against your inside thigh for a concentration curl, you lift the dumbbell as high up to your chest as possible, which stress the final range of elbow flexion. In all forms of biceps curls, straighten your arm when completing a rep to benefit fully from the exercise.

    Advantages

    • Isolation exercises, such as biceps curls, allow you to go that extra mile in a workout. After you’ve fatigued your arm muscles in compound exercises at the beginning of your workout, isolate and build your biceps with curls at the end of a training session. For this reason, use a curl machine, which doesn’t tax your core stabilizing muscles and also guides the weight. Since you don’t have to spend as much effort on balance, you can use heavier weights on a curl machine and focus on building your biceps muscles.