The Ultimate Guide to Preacher Curls

Bicep curls are a staple exercise for any strength training program. The preacher curl is one of the most popular curl variations for gym-goers looking to build their biceps.

However, preacher curls have been a topic of controversy in fitness and bodybuilding subcultures due to injury concerns. Yes, (overly) heavy preacher curls can increase the risk of biceps tendon tears, but that doesn't mean preacher curls are "unsafe."

No matter what type of training experience you have in the gym, whether you're a long-time bodybuilder or a novice lifter, you can safely and effectively build bigger biceps with preacher curls. 

Follow along as we explore the preacher curl, how it affects forearm and biceps growth, and some excellent preacher curl variations that we recommend adding to your fitness repertoire. 

What's a Preacher Curl?

Preacher curls are a classic variation of the traditional biceps curl. This isolated exercise uses an EZ bar, a multi-angled barbell designed to work the upper arm muscles without putting strain on the elbows or wrists, along with a preacher pad to create a low-impact lifting environment for muscle growth. 

What makes the preacher curl so unique is that it's incredibly versatile. Though a preacher bench creates an optimal angle for the bicep curl, this exercise can also be performed using a regular inclined bench or an exercise ball. You can also use a preacher curl machine or dumbbells if you don't have access to an EZ bar.

Like any regular bicep curl exercise, preacher curls are a single-joint, isolated exercise that targets both the biceps and forearms. 

• Biceps and Brachialis – the biceps and brachialis are the primary muscles used during the preacher curl. The biceps brachii muscles, which separate into both a long head and a short head, are both activated during the curl. However, due to the angle of the preacher bench pad, the upper arms are positioned higher than normal, which puts the shoulder joint into flexion and causes the long head to stretch more during extension [1].

• Forearm Flexor Muscles – The forearm flexor muscles are activated during the preacher curl to help move the elbow through extension and flexion. The forearm flexors also contribute to grip strength to keep the wrist in a neutral position during the curl movement. Considering the EZ bar's unique shape, the forearms can adapt to multiple grip options, making this exercise more versatile than most other variations of biceps curls.

Benefits of the Preacher Curl Exercise 

The preacher curl brings a number of benefits that you can't find in a traditional bicep curl. Here are three unique benefits of the preacher curl.

1. Targeted and Isolated Exercise 

Using a preacher bench pad to keep the shoulders and elbows in place, this curl variation forces the biceps to work without support from the shoulders or back muscles. Without allowing you to use any momentum to lift the bar, the preacher curl puts more emphasis on these muscles which can lead to increased strength gains. 

2. Focuses on Eccentric Loading 

A critical feature of this curl is that it focuses more on the negative or eccentric movement. The eccentric phase, also known as the muscle lengthening phase, is used to store energy within our connective tissue to eventually be transferred into concentric or lifting power. 

The stability of the preacher bench allows you to perform a slow, controlled eccentric phase to generate more power through constant tension. As a result, the transfer of stored energy is used to help maximize muscle growth and strength potential through the biceps [2, 3]. 

3. Increased Comfort and Stability

Another benefit of the preacher curl is the added comfort and stability you have throughout the movement pattern. Although you are placing a load onto the biceps, the preacher curl bench helps make this exercise feel very natural. The subtle 'W' shape of the EZ bar also places your wrists at an ideal angle to minimize pain or discomfort. 

How to Perform Preacher Curls with Exceptional Form

As mentioned earlier, there are various ways to execute the preacher curl. For the purpose of form and mechanics, we will discuss the traditional preacher curl using an EZ bar with an underhand grip (supinated grip) and angled bench pad. 

1. Begin by selecting a lighter-weight EZ barbell and placing it on the front bar rest of the preacher bench 

2. Adjust the height of the seat so that your upper arms and chest are both in contact with the pad (your armpits should be hovering over the top edge of the bench) 

3. With your upper arms resting on the pad, lean forward and grab onto the EZ-curl bar with an underhand grip with your hands shoulder-width apart 

4. Maintain a neutral wrist position with your arms extended 

5. Begin curling the bar up by contracting your biceps and flexing your elbow, lifting the bar to shoulder height 

6. Slowly lower your arms back down to starting position by elongating the bicep muscles to maximize their full range of motion

7. Repeat these steps for your desired number of reps

Preacher Curl Variations 

There is a wide range of preacher curl variations that all help to maximize your strength and muscle gains. Here are our top 3 favorites.

1. Thumbs overhand preacher curls

If you're looking for a way to level up the standard preacher curl, the thumbs overhand technique is the way to go. This method not only helps to build grip strength, but it's also a great technique to capitalize lower arm training. 

Setting up as you would with the classic preacher curl, you'll want to hold the bar in an overhand grip using just your fingers. With your thumbs tucked into the overhand grip rather than being wrapped around the bar, you'll experience greater tension on the lower arms to balance the weight of the bar solely using your forearm flexor muscles.

2. Zottman preacher curls 

Another popular variation is known as the Zottman preacher curl. This exercise uses a rotating grip that changes from underhand/supinated during the lifting/contraction phase to overhand/pronated during the lowering/eccentric phase. For this reason, the Zottman variation can only be done using dumbbells.

Unlike barbell preacher curl variations, the added rotation during the Zottman curl helps increase tension in the forearms, biceps brachii, and brachialis which may lead to greater strength gains [4].

3. Hammer Preacher Curls 

The dumbbell hammer preacher curl is another excellent variation that uses a neutral wrist position throughout the entire movement. This curling technique benefits lifters in two ways. First, the grip used is stronger than the supinated or pronated positions, making it possible to lift more weight or perform more reps. Secondly, these dumbbell preacher curls restrict rotational movement of the wrists which may reduce strain on the elbow and shoulder joints.

Key Takeaways 

Preacher curls are an effective exercise to build strength, power, and definition in the biceps and forearm muscles. Compared to regular bicep curl exercises, the EZ bar preacher curl creates the most natural angle of movement for the elbow to help stabilize the joint while also optimizing eccentric loading capacity.