Biceps 21s: Benefits, Alternatives & How To Do It Correctly

21s don’t just pertain to Blackjack. 21s more specifically, Biceps 21s are an altered variant of the curl bicep, which will help you build bigger guns.

You might be asking “what exactly are the biceps 21s?”. In short, bicep 21s, also known as “21s” in short form, is a biceps’ curls broken down into three different ranges of movements.

Seven partial reps are performed at the bottom and seven reps in the top portion of the movie, and finally seven repetitions to complete the complete biceps curl.

Learn more about the place where biceps 21s originated, their advantages, the muscles that were used as well as several variations that you can try to become stronger.

What Is Biceps 21s?

Biceps 21s is an exercise centered on the biceps curl but is broken into three distinct moves. Bicep 21s consists of three sets of seven reps performed with no rest.

The initial two sets consist of partial reps, and the final set is complete range. In the initial set, you perform partial reps of a biceps curled from the starting position to the point where your elbows bend at 90 degrees.

Then, you’ll repeat seven reps in the second part of the exercise starting from the point where your elbows are bent in 90-degree increments until finish the curl.

The final set of seven reps will encompass the full range of motion, moving your arm to the full extension and flexion. There is no time for rest between the three mini-sets.

The three sets are a series of reps that total 21.

Who Was The Creator Of The Biceps 21s?

Biceps 21s Benefits

The question of who invented the biceps 21s workout isn’t as simple.

There are several people to mention who could have played an influence in the creation of this powerful arm-building exercise.

Let’s start with the man who attracted all the attention of 21st-century biceps, Arnold Schwarzenegger.

Arnold was adamant about the bicep workout to build weight on his arms. In 1985, the Encyclopedia of Bodybuilding was published in which Arnold was quoted as saying that the 21s were the best.

You can guess that Arnold’s reference to the exercise prompted people from all over the world to take up Bicep 21s.

In this case, we can safely claim that Arnold was the first to popularize this technique However, he never acknowledged that he had created it.

Other people who are often associated with the biceps 21s exercise include Vince Gironda, Wag Bennet along with Dr. Ron Laura.

Beginning with Vince Gironda, some people believe that he was the first person who invented the 21st century. Gironda is among the most prominent bodybuilding legends and has several exercises named in his honor, like the Gironda pullup and Gironda dip.

Some claim that Gironda invented 21s but that it was later referred to as Super 21s. We haven’t found much evidence to confirm this however it’s possible.

Then comes Dr. Ron Laura is the only person who claims to have invented the 21st century. Dr. Laura is best known for his Matrix training system. He claims that he thought up the concept of biceps at 21, when the age a child, to keep up with his brother and friends as they were lifting weights. Laura.

Laura eventually created 48 Matrix Principles based on partial repetitions of different movements that target the entire body. Laura was a doctor.

Laura ended up becoming acquainted with the famous Joe Weider and wrote his books. Weider played a major part in Arnold’s success and this could have been the reason why Arnold gained his 21st birthday.

In the final analysis, we must consider Wag Bennet. Bennet came across Arnold during a bodybuilding contest held in London just before Arnold became a world-renowned sensation.

Bennet eventually invited Arnold to his home and guided him to his first title in bodybuilding.

Even though Bennet did not claim to have invented the 21s bodybuilder of the past, Lee Labrada said that Bennet taught him this workout when during his time in London.

With one doctor Dr. Ron Laura claiming that he invented the biceps 21s and we’ll take Ron Laura as the person who created the exercise even though the origin story behind the exercise isn’t quite as clear as many others.

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Biceps 21s: Working Muscles

Bicep 21s Instructions, Benefits, Alternatives & Variations

Primary Muscle Groups:

Biceps 21s mostly work on the brachial muscles of your biceps. The bicep muscle is made up of two “heads:” a long head and a shorter head. Both heads work to form a cohesive unit when pulling and lifting motions.

This bicep curl concentrates on the brachioradialis muscle which is one of the strongest and most visible muscles of the forearms. The principal duties of the brachioradialis forearm flexion and supination as well as pronation.

Secondary Muscle Groups

Bicep 21s are a second exercise that works your brachialis muscles, which is a muscle located in your biceps. It is situated under the brachii of your biceps. This workout also targets your back muscles and abdominal muscles, since they are activated to keep your body in place when you curl your body.

Other muscles in the forearms are involved in the biceps 21s.

Biceps 21s: Benefits

#1 Size And Strength Gains

Biceps 21s is an extremely effective compound bicep workout. In comparison to conventional Bicep curls, bicep 21s increase the time under tension throughout the exercise. This means that the longer time under tension helps strengthen the biceps muscles and increases the hypertrophy of the biceps.

The biceps you build isn’t just for show; they can improve your performance when you do other exercises in the gym, such as barbell row barbell rows and pulling down the pulling down of the lat.

#2 Forearm Activation

Biceps 21s provide the advantages of two workouts at the same time, as they target the biceps as well as forearms simultaneously. In the bicep curl 21s, your forearms are constantly working to support your arms through each stage of the lift. So you will benefit from strengthening both arms simultaneously.

#3 Improved Aesthetics

Let’s face it, most people want arm muscles that look better. Based on your goals it is possible to use the bicep 21s for developing larger, more toned, and more defined biceps or forearms. While this is a challenging workout, it’s relatively easy to master and can assist you in improving the appearance of your arms within a short time.

Biceps 21s: Instructions


To perform this bicep curl set exercise, you’ll need two dumbbells or a barbell, an EZ bar, or a different type of resistance that allows you to curl.


  • Grab your favorite form of resistance by using the supinated grip of your hand.
  • Take a standing posture in a comfortable stance, with your hands at your sides.


Phase #1

  1. Keeping your back straight, activate your core, and then contract your biceps. They will curl up till your arms are level to your elbows.
  2. Take a break for a few seconds then return to the beginning position. Repetition this curl six times to complete seven repetitions.

Phase #2

  1. Start from a half-curl where your hands are in line with your elbows tighten your biceps in the upward direction until they are at your shoulders.
  2. Press your biceps tightly at the top before returning to your starting position. Repetition this half curl 6 times to complete seven repetitions.

Phase #3

  1. Finally, pull your hands down by your sides and tighten your biceps until they curl to the upwards position to bring your hands to your shoulders.
  2. squeeze your biceps with a firm squeeze at the top, then return to the beginning position. Repeat the full bicep curl six times, for a total of seven repetitions.
  3. You have successfully completed the bicep! Repeat the process until you have reached your set number.


If you’re unfamiliar with the 21s bicep curl select a weight that is light to start. You can utilize the 21s bicep as a single time finishing Bicep exercise or do three or four sets of 21s bicep for a complete workout.

Biceps 21s: Mistakes

Biceps 21s Instructions

#1 Rounding The Back

Many weightlifters will round their backs during their 21s Bicep Curl. This position of the back that is rounded frequently occurs when fatigue sets into the final stages of the workout. A back that is rounded can compromise the spine’s safety and could lead to injuries.

Choose the lighter weight, and ensure your back muscles are working to test your biceps the safest way.

#2 Utilizing Momentum

Most of the time it is commonplace for people to move their arms and utilize momentum to increase their weight during Biceps 21s. Most of the time, this is because they attempt to lift too the weight.

Instead of letting ego hinder your progress Choose a weight that is lighter and concentrate on improving your posture. Being mindful when lifting lighter weights will improve your performance and lower your risk of getting injured!

#3 Rushing The Motion

Another mistake that is often that is made during the Bicep 21s is to rush. That is, they go through the curl quickly and let the dumbbells drop rapidly to the bottom in the order to “make the most of” the exercise.

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This error can negate the gains that could be gained in the eccentric part of the exercise movement.

Instead of racing through the movement, you should curl upwards and downwards slowly and in a controlled way. This is not only more secure, but it will also improve your endurance and increase the effectiveness of Bicep 21s.

Biceps 21s: Tips & Tricks

Biceps 21s Alternatives

Don’t Rock: Lift the weights with controlled movements throughout the workout. It is common to see people trying to perform 21s by bouncing their bodies or using their legs to help move their weight up. But, if you’re using momentum to lift the weight, you might be lifting weights that aren’t enough heavy.

How To Fix: You could try to perform biceps 21s sitting down if you’re using dumbbells, so it’s difficult to generate an energy source to raise the weight. Try preacher curls 21s to avoid any movements at the elbow.

Select The Correct Weight: With this exercise, it’s 21 repetitions at a time without breaks and therefore the weight or the resistance that you’re using shouldn’t be excessively heavy. When lifting to increase hypertrophy, you’ll be in a range between 6-12, and you’ll have to reduce the amount of weight that you’re performing compared to doing the standard set of Biceps Curls.

How To Fix: Begin with light to moderate weight during your initial set to see how much you can go without impacting your appearance.

Switch Equipment Up: Your body will change and adapt to the same workout stimuli in time, which is why it’s essential to keep shocks to the muscles. It is possible to shock muscles by a variety of methods, such as switching equipment as well as sets and reps. the methods of training, grip, and body posture.

How To Fix: Do biceps 21s using different equipment like kettlebells, dumbbells, resistance bands, or even the cable machine. Adjust your body’s position and also from standing or sitting down to a prone posture.

Take Your Time: Bicep 21s will result in the best results if you are doing them slowly and in a controlled movement. A lot of people begin swinging the weights upwards and downwards to finish the exercise in the quickest time possible since it’s a difficult exercise that makes those muscles burn.

How To Fix: Concentrate on the contraction of your muscles during every repetition. As you lower the weight, consider using longer eccentric phases for 3 to 5 seconds.

Adjust Weights: The different phases of biceps 21s puts different strains on muscles. The initial portion of the lift that starts mid-way can be completed easily and the final portion is easy to do.

The midpoint is where the majority of people are stuck since this is the most difficult movement to master. Adjust to the curve of strength by adjusting the weights you lift.

How To Fix: Try using three different weights to perform the biceps 21s. For instance, try using dumbbells of 25lbs for the initial seven reps. Then, try the following seven partial top-end reps using 30lb dumbbells. Then, reduce it to 20lb dumbbells for the final seven reps in the entire range of motion. These are the most difficult reps to do.

Alternative Rep Range This exercise has been named bicep 21s because you’re performing 21 total reps. You can alter the rep ranges but remain within the realm of hypertrophy that could be possible. Certain studies have shown that hypertrophy is still occurring when reps are set to 40.

How To Fix: Try changing the standard seven rep intervals for each of the 21s. You can increase or decrease the reps. You can try 5, 5, 5 as well as 10, 10, 10. The muscles are shaken as one method to increase muscle strength.

Utilize Different Body Positioning The original biceps 21s closely resembles the sitting biceps curl. Your muscles and body could be conditioned to perform curls that the biceps can cause, which could hinder the growth of your muscles.

How To Fix: You could attempt biceps 21s with an incline bench. You can do it lying on your back. It is also possible to set an exercise bench underneath the cable machine, then lay down on it and reach upwards to grasp the bar. Perform the 21s by pulling the bar towards your head.

Grip Switch: A lot of people use the same size grip when doing curls. It’s crucial to alter the width and the type of grip that you employ to work all parts of the arms and biceps generally.

How To Fix: Try using a grip that is narrow to strike the biceps’s inner part and then switch it to a wider grip to strike the biceps on the outside. It is also possible to play with grips such as the reverse or overhand curl as well as a neutral grip, or the hammer curl.

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How Many Sets Of Biceps 21s Do I Need?

Biceps 21s Variations

Biceps 21s can be treated as you would every other workout. You can do 3-4 sets with other bicep exercises. You could also make Bicep 21s the sole Bicep exercise and work on 5 sets or more. At the end of the day, it is important to get your biceps exhausted and do as you need to set it, do it.

However, at some point instead of doing endless sets increasing your weight load is the most effective (as long as you’re able to do the repetitions with good technique).

In general, we’d recommend that you should limit yourself to 6-8 sets per workout with the idea of trying to do 10-15 sets total for the biceps every week.

Biceps 21s: Variations

#1 Reverse Biceps 21s

Reverse 21s Bicep Curl is designed to target your forearms better than the traditional biceps 21s. Start in the same position as the first but twist upwards, with your palms facing downwards.

In addition to this change, the format remains the same!

#2 Dumbbell Hammer Curl Biceps 21s

As compared to the standard bicep 21s the hammer grip variant in the 21s Bicep Curl stimulates the brachialis muscles in the upper arm. Start in the same position as the first and then move the dumbbells upwards while keeping your palms together using an even grip.

Complete the bicep 21s in the same format as the first.

#3 Straight Bar Biceps 21s

You could also do the bicep 21s using an exercise machine. Stand in the front of a cable machine, and place your straight bar’s attachment in its lowest position. Hold the straight bar using an uninvolved grip.

Engage your core while you perform the Biceps 21s using the same form and shape as the dumbbell, barbell, or an EZ bar variation. Repeat!

Biceps 21s: Alternatives

If you liked the biceps 21s, you should check out these alternate exercises that will help you improve your bicep workout:

#1 Dumbbell Zottman Curl

Take a dumbbell with your palms in front. Stand up with your feet about an inch apart.

Keep your back straight and straight, tighten your biceps until you can lift the dumbbells up. Make sure you squeeze your biceps at the top and then twist your hands to ensure that your palms are facing downwards.

Then slowly lower the dumbbells back to the starting position, then twist your hands until your palms face toward the front. Repeat!

#2 1-Arm Kettlebell Biceps Curl

Make sure you are in a comfortable posture while keeping your body straight. Hold a kettlebell with your right hand, and keep your palm facing toward the front. Engage your right bicep to pull the kettlebell up. Press your bicep to the high point of the rep. Then slowly return to your starting position.

Repeat until you reach the desired amount of reps and then switch to the left side!

#3 Close Grip Barbell Curls

Make sure you are in a comfortable posture with the back in a straight position. Take a barbell in a supinated double grip and keep your hands together. Engage your biceps in a curling motion to pull the barbell upwards.

Make sure you squeeze your biceps to the top, then slowly return to the starting point. Repeat!

Last Words

Biceps 21s is an ideal exercise to build strong arms.

You can also apply this training method to other exercises and get the same benefits from overworking the muscles with more duration under tension and different rep ranges that result in the sensation of a huge increase in the pump.

It is possible to apply the 21s method of training to other workouts as well and be inventive. You must keep the workouts exciting.

So the next time you’re feeling stuck or you want to end your workout with a challenging exercise take a biceps 21s shot.


  • Timothy P. Carnes

    Timothy P. Carnes is a certified personal trainer with a Bachelor's degree in Exercise Science from the University of Florida. With over 8 years of experience in the fitness industry, Timothy is an expert in strength and conditioning, body composition, and overall health and wellness. He also holds certifications in strength and conditioning through the National Strength and Conditioning Association (NSCA) and corrective exercise through the National Academy of Sports Medicine (NASM). As an author at FitGAG, he shares his knowledge and expertise on a variety of topics, including strength training, body composition, and overall health and wellness tips. Timothy believes that consistency and discipline are the keys to achieving fitness goals, and he strives to inspire his readers to prioritize their fitness and wellness journey. Through his articles, Timothy aims to empower his readers to take control of their health, enhance their performance, and live their best lives.

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