The most prominent focus of the upper body is your biceps.
Believe it or not, the biceps have finally received the recognition they deserve.
However, growing them requires specific exercises like dumbbell 21s to unlock their full growth potential.
Just imagine performing 21 reps across two sets in one go—pretty cool, right?
The amount of constant muscle tension this exercise produces is insane.
By pumping your biceps in three different phases, they have no choice but to grow.
However, achieving this growth requires effort and proper technique.
It’s crucial to learn the basics and the correct techniques for 21s to provide your biceps with the perfect environment to flourish and grow.
What Muscles Do Dumbbell 21s Work?
The dumbbell 21s variation of biceps curls provides impressive muscle work.
The exercise consists of two sets at once, which activates all the important muscles in your arm, making them look bigger.
While the primary target is the biceps brachii, your biceps are not fully activated at first.
During the first and second lifting phases, your forearm muscles react more than your biceps because you are not squeezing your biceps at the top.
However, the last phase fully activates your biceps.
As mentioned earlier, the forearm muscles react first.
Not only do your forearm muscles react during the motion, but the brachialis muscle also gets activated.
How to Do Dumbbell 21s
Equipment: Pair of Dumbbells
Grip: Supinated Grip
Primary Muscle Work: Biceps Brachii
Instructions
- Grab a pair of dumbbells and stand with your chest up, shoulders back, and eyes forward.
- For the first seven reps, curl the dumbbells from the bottom position to midway up.
- For the next seven reps, curl from the top position to midway down.
- Finally, complete the exercise by curling from the bottom all the way up to your chest for seven reps.
- Ensure you maintain proper form throughout the entire set.
Dumbbell 21s Pro Tips
- Mind the Tempo: Don’t rush. Use a slow and controlled motion, especially on the lowering (eccentric) part of each rep.
- Full Range of Motion: Even though some reps focus on partial curls, make sure you include a full range of motion in each set to fully engage the biceps.
Benefits of the Dumbbell 21s
Dumbbell 21s is an excellent exercise for arm growth due to its ability to target different aspects of muscle development.
Increased Strength and Size
The Dumbbell 21s exercise works your biceps through three motion phases.
These phases help your biceps gain muscle tissue and increase overall strength.
The two-half lifting phase is performed in a slow and controlled manner.
You contract your biceps through tension with seven repetitions midway up and seven midway down. This method activates different fibers in your biceps, which leads to overall biceps development.
Time Under Tension
The more your biceps are activated, the greater their chance to develop faster.
The 21s reps have a longer duration compared to regular biceps exercises. This extended duration allows the exercise to continuously provide tension to your biceps, which stimulates muscle growth.
Maintaining time under tension also helps increase your durability, making it beneficial for lifting heavy weights.
Common Mistakes
Uncovering the key to unlocking true potential in any exercise often lies in understanding common mistakes. By identifying and avoiding these pitfalls, you streamline your journey, making it smoother and more effective.
Not Keeping Your Elbows Tucked
The elbow does a lot of movement during the curl.
Incorrect placement of your elbow can reduce muscle activation.
Your elbow should be loose and stay in a natural position when you hold the dumbbells.
You shouldn’t flare them out during the movement, as this prevents the muscles from being properly activated.
Keeping your elbows in the correct position ensures that your biceps and other muscles are fully engaged. This proper form is crucial for muscle growth, and avoiding mistakes like flaring out your elbows will help you see better results from dumbbell 21s.
Swinging the Dumbbells
Swinging the weights occurs when you move them with momentum rather than using isolated muscle control to raise and lower them. This behavior leads lifters to develop bad habits, which hinder their performance and affect their ability to perform other exercises.
Additionally, excessive swinging can result in lower back injuries and strains.
To avoid this, start with lighter weights and gradually increase the load as you progress.
Not Focusing on the Squeeze
Often, some new lifters just lift the weight without understanding the fundamentals of exercise.
They think that simply curling up and down will eventually give them the biceps they want. This leads to an unsatisfying workout experience because they do not see any results.
When performing dumbbell 21s, you should squeeze your biceps at the top.
A study on PubMed found that if lifters squeeze their biceps as hard as they can, it significantly helps with developing muscle mass and biceps growth. [1] This shows how important contracting your biceps is. The whole exercise can be worthless if individuals miss out on it.
Alternatives and Variations
- Dumbbell Curl
- Dumbbell Drag Curl
- Dumbbell Hammer Grip Bicep 21s
- Barbell 21s
Dumbbell Curl
The classic dumbbell curl has always been effective for growing big biceps. This exercise isolates your muscles well, which promotes significant growth by targeting both heads of the biceps.
Many other biceps exercises cannot achieve this same level of targeted muscle engagement.
Furthermore, the dumbbell curl can be performed with just a pair of dumbbells at home, making it a convenient and effective alternative to dumbbell 21s.
Dumbbell Drag Curl
The dumbbell drag curl targets your biceps differently than other dumbbell biceps exercises.
The movement requires you to pull your elbows back and drag the weights close to your body. This drag motion primarily activates your biceps while also engaging the brachialis, brachioradialis, and shoulders.
Using dumbbells helps with balanced muscle growth because the weights move separately rather than together, as they would with a barbell. This ensures that each arm works equally, promoting more even muscle development.
Dumbbell Hammer 21s
Also known as the neutral curl 21s, the hammer 21s is quite an unusual variation but quite impressive.
The three lifting phases help activate your forearms more than your biceps due to the neutral hand position.
However, this doesn’t mean that your biceps receive minimal tension. Performing this exercise could be more challenging, especially if you’re using weights that are not recommended.
Despite this, it’s a great variation of 21s that can be incorporated into any arm day routine, adding diversity and targeting different muscles effectively.
Barbell 21s
The barbell 21s are performed in the same way as the dumbbell 21s, but with a barbell.
The movement and targeted muscles are similar.
However, using a barbell has one major benefit that many lifters appreciate. It allows you to lift more weight, which can be beneficial for arm growth.
The more pressure you put on your arms, the more they grow.
However, overloading the bar can have the opposite effect.
It’s important to use the proper technique when lifting heavy objects to ensure your muscles grow and you avoid injury.
References
- Schoenfeld BJ, Vigotsky A, Contreras B, Golden S, Alto A, Larson R, Winkelman N, Paoli A. Differential effects of attentional focus strategies during long-term resistance training. Eur J Sport Sci. 2018 Jun;18(5):705-712. doi: 10.1080/17461391.2018.1447020. Epub 2018 Mar 13. PMID: 29533715.
Featured image by antondotsenko/iStock edited by SA
