To really allow your biceps to reach their full potential you may need to start adding 21’s to your biceps’ routine. The number “21” refers to the number of total reps you do in one set. However, this particular “21” is divided into three 7-rep segments that ultimately target the entire bicep.

1st 7 Reps: For the first seven reps, go from the bottom of the movement up to the halfway point (with your arms at a 90 degree angle and hands at elbow level).

2nd 7 Reps: Go from the halfway point up to the top of the bicep curl (hands up near shoulder level).

3rd 7 Reps: Start at the bottom of the movement and complete a full range of movement all the way up.

How To Perform 21s 

  • Stand upright and grab a barbell with an underhand grip.
  • Place your hands shoulders-width apart and allow your arms to hang toward the floor.
  • Tuck your elbows tight to the sides of your body.
  • Curl upward until you make a 90-degree angle at your elbow.
  • Relax your arms back to full extension and repeat six more curls reaching the 90-degree angle at your elbow.
  • Now, from the 90-degree at your elbow position, curl the weight up until the barbell is one to two inches away from your shoulder.
  • Lower the weight back to the 90-degree elbow position and repeat six more times.
  • Now, allow your arms to return to full extension.
  • This time, curl your arms from full extension all the way to full extension. Keep curling until the bar is about one to two inches away from your shoulder.
  • Repeat six more curls through this full range of motion to complete a total of 21 curls.