The Oldest (and Best) Way to Build Bigger Biceps

Bicep Curls

Photo via Thinkstock

If you want big biceps but you're sick of doing endless reps of Bicep Curls, taking time away from exercises that will actually make you a better athlete, try Bicep 21's, a method bodybuilders use to get an arm pump.

Bicep 21's goes like this: Perform seven partial reps of Curls going only halfway down, another seven going only halfway up, and finish with seven full range Curls, for a total of 21 reps.

RELATED: Build Bigger Arms in Two Minutes

Here's a video of bodybuilder Ronnie Coleman performing Bicep 21's as a part of his arm workout:

Although this method is very effective, at Performance U we re-invented it to create new muscle gains from an old concept. Put simply, we modified Bicep 21's based on science and muscle physiology, not tradition.

The Science Behind Bicep 21's 2.0

Bicep 21's will give you an incredible pump by increasing the time under tension (TUT)—the amount of time your muscle is resisting weight. Increasing TUT increases metabolic stress, one of the three mechanisms for building bigger muscles.

RELATED: Big Arms Fast: A Scientific Approach

The biggest difference in our 2.0 version of Bicep 21's is our focus on the mid-range of the Curl, due to the principle known as the length-tension relationship. Muscles have the lowest potential to generate force when they're either fully elongated (stretched) or fully shortened (contracted). They generate the highest possible tension exactly in the middle. We take advantage of this.

Biceps 21's: Performance U Style

Now that you understand the scientific rationale for why we modified Bicep 21's, let's look at two practical applications we developed to take advantage of these principles.

LIFT LIKE THE PROS: Tiki Barber's Bicep Routine

Biceps 21's (Version A)

You can perform this protocol using dumbbells (as shown in the below video), a barbell or an EZ-Curl bar.

  • Mid-Range Partial Curls x 7
  • Isometric Mid-Range Holds w/ Wrist Pronation-Supination x 7 seconds
  • Full Range of Motion Curls x 7

Biceps 21's (Version B)

Perform this protocol using two sets of dumbbells. Begin with the lighter set and perform the first exercise. Then switch to a pair that is five pounds heavier to perform the other two exercises.

  • Leaning Biceps Curls x 7
  • Switch to heavier dumbbells
  • Isometric Mid-Range Holds w/ Wrist Pronation-Supination x 7 seconds
  • Full Range of Motion Curls x 7

Read More:


  • Schoenfeld BJ. "The mechanisms of muscle hypertrophy and their application to resistance training." The Journal of Strength and Conditioning Research. 2010 Oct;24(10):2857-72.
  • Lieber, R.L., & Bodine-Fowler, S.C. (1993). "Skeletal muscle mechanics: Implications for rehabilitation." Physical Therapy. 73, 844-856.
  • Smith, L.K., Weiss, E.L. & Lehmkuhl, L.D. (1996). Brunnstrom's Clinical Kinesiology (5th ed.). Philadelphia: F.A. Davis.
  • Winter, D. (1990). Biomechanics and Motor Control of Human Movement. New York: John Wiley.