Build bigger arms with biceps 21s: Understanding its form and benefits

If you want to give your arms a killer workout, consider adding biceps 21s to your routine. Also known as a 21s bicep curl, it's an intensive exercise that’s sure to put tension on the biceps and help improve overall arm strength and size.

Not only does it fully activate the biceps, but it also strengthens the forearms and enhances endurance of the biceps. It increases metabolic stress and time under tension while giving the biceps a massive pump and growth.

Muscles targeted by biceps 21s

Biceps 21s target the biceps brachii and brachioradialis. (Photo via PexelsPikx By Panther)

Workout 21s primarily target the biceps brachii and brachioradialis. While the biceps brachii is a thick, large muscle located in the upper arm, the brachioradialis is the strongest and the most visible muscle in the forearm.

The secondary muscles targeted by biceps 21s are the brachialis, abs and back muscles. The brachialis is located beneath the biceps brachii.

How to do the biceps 21s correctly?

To do this exercise, you will need a barbell, an EZ bar, a pair of dumbbells or any other free weight of your choice.

21s bicep curls comprise three sets of seven reps (total 21 reps), which is what gives this exercise its name. During the first two sets, you have to perform partial reps, but in the last set, you have to execute a full range of motion. Each set involves a different variation of this exercise.

For the 1st set: Curl from the bottom of the movement, and go up to the halfway point, with the arms at 90 degrees and at elbow level.

For the 2nd set: Curl from the halfway point to the top of the bicep curl with the hands reaching shoulder level.

For the 3rd set: Begin from the bottom, and go for a full range of motion.

Here’s how you do the barbell 21s:

Stand straight, and grab a barbell or any other form of free weight using an underhand grip. Keep the abs engaged and arms straight, and pull the shoulders back and down.
Bend your arms, and curl the barbell up till the elbows get bent to a 90-degree angle and the forearms are parallel to the floor.
Slowly lower the barbell, and repeat the movement seven times.
From 90 degrees, curl the barbell up to shoulder level, and lower it down till the forearms get parallel to the floor. Repeat for 7 reps.
Lower the barbell down, and repeat for seven reps. Move from full extension to flexion in this set.

Tips to make the exercise easier

To get the most out of biceps 21s, remember the following tips:

Always start with lighter weights: When doing this bicep-building exercise, always start with a lighter weight, especially if you're new to strength training. Light weights will keep your form in check and also prevent the swinging of the weights.

Do not use momentum: When executing the curl movement, remember to lower and raise the weight slowly and with control, as that will help keep the entire tension on the targeted muscles.

Don’t rush during the last reps: Avoid rushing to complete the last seven reps, as that can make the exercise less effective, and you could also end up getting a muscle strain.

Keep your spine straight: Aoid rounding or curving the spine as that can lead to back pain and injuries.

Benefits of bicep 21s

Keeping the spine straight is important. (Photo via Pexels/Andrea Piacquadio)

The biceps 21s is an excellent exercise that helps maximize time under tension, which increases hypertrophy and builds bicep strength. It targets the forearms and biceps at once while giving an intensive lower and upper arm workout.

Depending on your fitness goals, you can do this exercise to build bigger, more defined or more visibly appealing biceps. Overall, biceps 21s can help improve the appearance of arms and build massive strength in the forearms and biceps.