Bicep 21s for Building Bigger Biceps

Nearly everyone who enjoys a hardy workout routine hopes to build bigger arms. For that, you need an intensive movement exercise that really puts tension on your biceps. Not only can bicep 21s help you reach this goal, it is one of the relatively simpler exercises to learn.

If you have come across Arnold Schwarzenegger's Encyclopedia of Modern Bodybuilding, you will be familiar with bicep 21s. It is a part of every bicep workout as the classic exercise that helps your biceps reach their full potential.

So let's jump right into it!

How To Perform The Bicep 21s

To do this exercise, you need a dumbbell weight for each hand to hold. The number "21" in bicep 21s or 21s bicep curl refers to the total number of reps you need to do. You divide 21 into three sets of total seven reps per arm. Each set compromises a different variation of this bicep exercise for a full range of motion.

Stand upright on your feet with your hands hanging on either side towards the floor for all sets. Legs should be about shoulder-width apart here. Read on to get the step-by-step instructions for executing these bicep sets correctly.

Bicep 21s - Set #1

1
Go from bottom to halfway up, where your arms are at a 90-degree angle and hands are at elbow level.
2
Grab the two dumbbell weights and keep them on either side. hold them with a neutral grip, with your palms facing your torso.
3
As you keep your back straight, hammer the curls up by engaging your core and contracting your biceps. While doing so, do not rotate your wrists.
4
Half curl upwards until the hands are aligned with your elbows.
5
Pause for a moment and then lower them back to the bottom position.
6
Repeat this half curl six more times to complete 7 reps.

Bicep 21s - Set #2

1
Go halfway up top to your biceps near the shoulder level.
2
Once you are at the starting position, hold the dumbbell weight with a supinated or underhand grip. This means the palms got to face forward.
3
Curl the weight upwards from the 90-degree angle elbow position until you are one or two inches away from shoulder level.
4
Pause for two or three seconds as you contract your biceps up top. Then, begin lowering the dumbbells down.
5
Complete the 7 reps.

Bicep 21s - Set #3

1
Do the hammer curl from the first set. The only difference is that you will go up across the body.
2
Start with either the left or right arm and hammer curl the dumbbell weight up.
3
As you go upward, go across your body or torso, and keep going up until you reach your upper chest, near the shoulder level.
4
Hold for a second or two, and then bring the dumbbell back down.
5
Repeat six more times before switching to the other arm to complete 7 reps.

What Are Bicep 21s?

Troy performing bicep 21s with dumbbells at the gym

Bicep 21s, also known as 21s bicep curl, is a compound exercise that works your biceps and forearms. Your forearms and biceps get activated as you use them to support the weight lift. As you do this, bicep 21s increases the time under tension. Increased time under tension strengthens your bicep muscles and increases bicep hypertrophy.

While doing bicep curls, you work the primary muscle group consisting of brachii and brachioradialis.

Both lie at the elbow joint and are responsible for pronation, supination, and forearm flexion. It will also work upper arm muscles like the brachialis that lies beneath the brachii and helps out with elbow flexion.

Although meant for bicep training, bicep 21s also work your abs and back. They get activated as you attempt to stabilize your body during the curling motion.

Tips For Maintaining Correct Form

If you want your fitness workout to give your biceps more muscle and strength, be mindful of your posture. A good posture minimizes the possibility of muscle strain or injury.

Here are some tips on how you can keep the correct form while doing this bicep curl movement.

Focus On Keeping Your Spine Straight

This tip applies to every workout routine or fitness training exercise. As you progress to the next rep, you got to remain conscious of whether your spine is straight or not. With these bicep reps, fatigue can creep up on you towards the end. This can result in a rounded back position which can hurt your spine.

Lower Dumbbells Slowly

Troy lowering the dumbbells during the bicep 21s exercise

When you lower the dumbbells back to the bottom, do it slowly and gradually. Those who are new to such exercises will try to rush through this part of the exercise. Perform the curls in a slow and controlled manner so you can reap the full benefits of this range of motion.

Do Not Depend On Momentum

Troy performing the bicep 21s exercise with dumbbells without momentum

When doing such bicep exercises, most individuals make the mistake of swinging their arms. They follow this technique to use the momentum from the arms to quickly be done with the bicep reps.

To avoid this, you can start with lightweight dumbbells and then work your way up once your strength increases.

Variations Of Bicep 21s

If this standard biceps curl comes to you easily, you can challenge yourself with more reps or other variants. Let's take a look at what these can be.

Straight Bar Bicep 21s

Dumbells are not a necessity with this exercise. To shake things up, perform it with a cable machine.

Stand in front of the machine, setting the straight bar attachment at the lowest level possible.

Then repeat the same pulling and lifting motion by grabbing the straight bar with an underhand grip for seven reps.

Barbell Close Curl

Just like dumbells, a barbell can also help you out with engaging your core and working your biceps.

Grab the barbell with a supinated grip and your hands closer than shoulders width.

Curl the barbell upwards with all your strength while contracting your bicep muscle.

Before you lower the dumbbells to repeat the desired number of reps, make sure to squeeze the biceps while at the top.

Tip: You can also perform the close bicep curl with an EZ curl bar.

Lying Bicep Curl

You can also do this curl exercise by lying on a bench! For your starting position, lie on the bench as you keep the dumbbells on your chest near your shoulders. It should look as though you are already in a bicep curl position.

Then, slowly lower the dumbbells towards the floor using your biceps. As you do this, focus on the contraction before bringing the weights from the bottom back to the top of your chest.

Pro tip: Use the One Rep Max Calculator to find the accurate number of reps you should be doing.

Final Thoughts

Safe to say, bicep 21s offer a full range of motion to build optimal muscle growth and strength. This fitness technique grows your biceps and improves your performance in other workouts like lat pulldown or bent-over row.

For this fitness routine to be effective, you should maintain a good diet and rest time. After every 7-rep set, you can rest your arms for about 2-3 minutes. You are now equipped with fitness information to build muscle with bicep 21s!