As a bodybuilder, I have tried the arm blaster and preacher curl to grow my biceps, and over the years I’ve noticed that there is some confusion about what the differences between them are and which one is better for bicep growth.
The arm blaster and preacher curl are two bicep isolation exercises that require specialty equipment. The arm blaster is the best option for those who have access to limited equipment, while preacher curls are the better option for commercial gym goers who have access to a preacher curl bench.
In this article, I’ll dive into the key differences between the two curl options so that you can determine whether one is better than the other or if you should include both in your program.
What is an Arm Blaster?
The arm blaster is a versatile and portable metal plate that fixes your arms to your sides. Anchoring the upper arms in place allows you to target and isolate the biceps when doing biceps curls.
This piece of equipment is great for those who have limited equipment to work with, like those who have a home gym, or apartment gym, or are frequently using hotel gyms, but still want to have higher-quality arm workouts.
What is a Preacher Curl?
The preacher curl is a curl variation that is typically performed using a specific piece of equipment (available at most commercial gyms) which is designed to fix the upper arms in place against a pad to help isolate biceps for bicep curls.
The preacher curl is a safe and effective way to improve your bicep curl technique by minimizing swaying and secondary muscle involvement so that you cannot “cheat” the movement.
The Science Behind Arm Blasters and Preacher Curls
To decide which is better for arm growth, it’s important to understand how they function.
How Arm Blasters Work
The primary muscle groups involved during the arm blasters are the biceps brachii long head and short head. The biceps brachii long head is located on the outer side of the biceps, while the short head is located on the inner arm.
Together these muscles are responsible for elbow flexion (bending) and also work to prevent elbow hyperextension.
Arm blasters target both heads of the biceps by anchoring the upper arm to the two outer pads. These two outer pads promote proper technique during seated and standing curls by preventing you from shifting your elbows backward.
Keeping your elbows forward while performing curls ensures that you’re keeping tension on the biceps during the concentric (lifting) and eccentric (lowering) portions of your curl.
By encouraging proper technique during bicep curls and forcing you to control your movements (rather than using momentum), the arm blaster can reduce your risk of injury and help you grow bigger and stronger biceps.
How Preacher Curls Work
The preacher curl works similarly to the arm blaster to target both heads of the biceps by fixing the upper arm in place against the pad.
However, the preacher curl is designed to position your arms out in front of you at a steeper incline, which places more emphasis on the short head of the biceps, otherwise known as the bicep peak.
The preacher curl is also generally performed seated, which can help reduce the use of momentum to lift the weight, reduce the involvement of secondary muscles, and take the stress off of your lower back.
Related Article: Best Arm Blaster Exercises + Sample Workout
Comparing Arm Blasters and Preacher Curls
While designed for similar purposes, there are some key differences between these movements.
Differences in Technique and Equipment
To do arm blaster curls, you will need access to an arm blaster which you will likely have to purchase as these generally aren’t available at commercial gyms. You’ll also need something to curl whether that’s a dumbbell, barbell, EZ curl bar, or resistance band.
1. Securely fasten the neck strap in a way that allows the metal plate of the arm blaster to comfortably sit at your upper abdomen/stomach.
2. Your arms should sit in the grooves on both sides of the arm blaster and lock them in place.
3. Either seated or standing, hold a dumbbell in each hand with your palms facing forward.
4. Raise the dumbbell while keeping your body as stable as possible.
5. Lower the dumbbells at a controlled rate to complete the repetition.
6. Repeat steps 4 and 5 for the desired amount of repetitions.
Preacher curls will require access to a specialized curl set-up, using a preacher curl bench and weights or a preacher curl machine.
How-To:1. Set up the preacher curl at a point that allows you to comfortably place your underarms over the inclined pad.
3. Starting from the top, lower your arms until they are completely extended.
4. From the bottom, raise your arms back to the starting position.
5. Repeat steps 3 and 4 for the desired amount of repetitions.
Differences in Muscle Activation and Strength Development
The arm blaster allows for one to be in a more advantageous position than the preacher curl because it involves a larger range of motion.
Ultimately, this means that the arm blaster produces greater muscle activation while also allowing you to lift more weight, which is ideal for developing strength and hypertrophy (growth).
Furthermore, if you get bored with the arm blaster variation that you’ve been doing, you can easily switch between either an EZ bar, barbell, dumbbell, or bands, while changing to either seated or standing for a more novel stimulus.
In contrast, the preacher curl has a more limited range of motion that isolates the peak of the bicep, resulting in less freedom for variation and lower loads lifted. While the lack of variation isn’t ideal, it is still an extremely effective exercise to isolate your biceps and promote hypertrophy (growth).
Arm Blasters: Pros & Cons
Benefits of Using an Arm Blaster
The benefits of using an arm blaster include:
The arm blaster can be used anywhere. The arm blaster can be used at home, at any gym setting, or on the go so there is no reason you have to miss out on a high-quality arm workout.
- The arm blaster is versatile. You can use the arm blaster with bands, dumbbells, barbells, or EZ curls bars and it can be used while standing or sitting. Its versatility makes the arm blaster compatible with any other pieces of equipment you have access to and promotes continued bicep progression, enjoyment, and longevity.
Drawbacks of Using an Arm Blaster
The drawbacks of using an arm blaster include:
The arm blaster costs money to purchase. The greatest barrier to using an arm blaster may be its cost and acquisition. Arm blaster alternatives such as incline bench concentration curls or preacher curls may prove to be more accessible and easy to implement into your training.
- The arm blaster may not fit in your gym bag. An arm blaster is a wide metal plate that likely won’t fit in your gym bag and could be a nuisance to carry around. This may not be an issue if you keep your arm blaster in a garage gym or store it at the gym you frequent.
Preacher Curls: Pros & Cons
Benefits of Doing Preacher Curls
The benefits of using the preacher curl include:
- Most commercial gyms have a preacher curl machine. The preacher curl machine is popularly placed in most commercial gyms. This makes it extremely accessible to most and doesn’t require you to make an extra purchase.
- Preacher curls are simple and easy to perform. Using a preacher curl machine is pretty straightforward, even for beginners. The simple learning curve allows you to add this to your program right away and see progress more quickly.
Drawbacks of Doing Preacher Curls
The drawbacks of using the preacher curl include:
- Preacher curls allow for less variation. Unlike the arm blaster, you cannot use as many variations and positions with a preacher curl machine. This is because the preacher curl machine or equipment is stationary and lacks the mobility of the arm blaster.
- Preacher curl machine alternatives are less effective. If you don’t have access to a preacher curl machine, the alternatives may be less effective at locking the arms in place. Furthermore, preacher curl alternatives such as an incline concentration bicep curl may be restrictive on body position and equipment implementation.
Choosing Between Arm Blasters and Preacher Curls
If you’re set on choosing one over the other, then there are some important factors to consider to determine which is best; however, if you’ve decided that you want to incorporate both movements into your training plan, then it’s important to do it correctly.
Factors To Consider For The Arm Blaster VS Preacher Curl
The 3 factors to consider are:
1. Your Fitness Level
The preacher curl is more straightforward and may be more effective for beginners.
The arm blaster is likely best for those who are more experienced and are experiencing plateaus in their progress.
The arm blaster allows for more novel stimuli by being more versatile with equipment usage, body positions (seated or standing), and arm positions (further or closer to the torso).
2. Equipment Availability
At a public commercial gym, it is less likely that there will be an arm blaster, however, there is a high chance that there’s a preacher curl stand or machine.
In contrast, at a garage gym, powerlifting gym, CrossFit gym, or Olympic weightlifting gym, there tends to be more limited access to machines and equipment. Therefore, it would be beneficial to invest in an arm blaster to improve your bicep routine.
3. Your Personal Preference
At the end of the day, it may be down to personal preference, and you might prefer either the arm blaster or the preacher curl.
I prefer to use the arm blaster when I am trying to have an intense workout. However, for my intense compound session days, I want my bicep accessories to be more simple, so I might implement preacher curls on these days.
How To Incorporate Both Into Your Workout Routine
If I were to incorporate both the arm blaster and the preacher curl, I would change my hand position for each of the movements.
With the arm blaster, I would implement palms facing towards the midline (hammer curl or neutral grip), which will target the long head of the biceps as well as the brachioradialis.
With the preacher curl, I would implement a variation with the palms facing upward (supination) to isolate the short head of the biceps and focus on developing a larger bicep peak.
Your bicep work could look like this:
- Seated preacher curls: 3 x 6-8
- Hammer curl arm blasters: 3 x 8-12
Frequently Asked Questions
Are arm blasters or preacher curls more effective for increasing muscle size?
Both arm blaster and preacher curls can be effective for increasing muscle size as long as it’s a novel stimulus. However, arm blasters have a higher potential for variation and implementation, giving them more potential to encourage growth compared to the preacher curl.
Will you be less prone to injury doing arm blaster curls or preacher curls?
You are less prone to injury during a preacher curl because you will most likely be in a seated position, which will take the stress off of the lower back. However, you can also do arm blasters sitting down, which may take similar amounts of stress off the low back.
Can beginners use arm blasters or is it more suitable for advanced lifters?
Anyone can use an arm blaster, regardless of their experience level; however, beginners need to start light and focus on proper technique to promote safe and effective repetitions.