Barbell Curl vs Concentration Curl: Which is Better for Bicep Muscle Growth?

The pursuit of building bigger and stronger biceps is a goal shared by many fitness enthusiasts. Two common exercises that are often debated for their effectiveness are the barbell curl and the concentration curl.

Both exercises target the biceps, but their distinct mechanics, muscle engagement, and overall benefits bring up the question: which is better for bicep muscle growth? In this article, we will break down the science behind each movement, exploring their pros and cons to help you make an informed decision.

We will also back up our findings with research and evidence-based insights to ensure you’re on the right path to bicep development.

What Are the Barbell Curl and Concentration Curl?

Barbell Curl

The barbell curl is one of the most classic and fundamental exercises for developing the biceps. It involves holding a barbell with both hands, palms facing up, and curling the bar upwards by flexing the elbows. The barbell curl primarily targets the biceps brachii, which is composed of two heads: the short head and the long head. This exercise also recruits muscles in the forearms and shoulders, making it a compound movement that engages multiple muscle groups.

Concentration Curl

The concentration curl, on the other hand, is an isolation exercise that targets the biceps in a more controlled manner. Typically performed seated, the concentration curl involves holding a dumbbell in one hand, bracing the upper arm against the inside of your thigh, and curling the weight upward by flexing the elbow. This exercise minimises involvement from other muscles and allows for a concentrated contraction of the biceps.

Muscle Activation and Biomechanics

When comparing these two exercises, it’s important to look at muscle activation and the biomechanics involved.

Barbell Curl Muscle Activation

The barbell curl allows for heavier loads due to the use of both arms working in unison. Studies show that the barbell curl activates both the short head and the long head of the biceps brachii to a significant degree. In a study published in the Journal of Strength and Conditioning Research, it was found that the barbell curl elicited greater overall biceps activation compared to other curl variations, primarily because of the bilateral nature of the exercise and the heavier loads used (Schoenfeld, 2010).

However, since the barbell curl is a compound exercise, there is also engagement from secondary muscle groups such as the forearms, brachialis, and deltoids. This shared involvement can somewhat reduce the focus placed solely on the biceps. Nevertheless, this broader recruitment can also be an advantage, as it supports greater overall upper body strength development.

Concentration Curl Muscle Activation

The concentration curl, as the name suggests, allows for greater isolation of the biceps. Research shows that unilateral exercises like concentration curls can generate higher muscle activation in the target muscle due to the focused tension. A study conducted by Oliveira et al. (2009) found that the concentration curl elicited the highest muscle activation in the biceps compared to various other curling exercises, including the barbell curl. This is due to the fact that the upper arm is stabilised against the thigh, minimising the involvement of surrounding muscles and maximising the isolation of the biceps brachii.

Though the concentration curl enables a greater mind-muscle connection and improved biceps isolation, the downside is that it generally uses lighter loads compared to barbell curls, which may limit the potential for progressive overload, a key factor in muscle growth.

Progressive Overload and Strength Potential

Barbell Curl and Progressive Overload

Progressive overload is one of the most critical principles in muscle growth. The ability to incrementally increase resistance over time forces the muscles to adapt and grow. Barbell curls are advantageous in this regard, as they allow for greater weight increments and more substantial load progression. Since both arms are working together, you can generally lift heavier weights, creating a more significant stimulus for hypertrophy.

In the long term, the barbell curl offers superior potential for building strength and size due to the capacity for heavier loads. Research supports the notion that mechanical tension, generated by lifting heavier weights, is one of the main drivers of muscle growth (Schoenfeld, 2010).

Concentration Curl and Progressive Overload

Concentration curls, while excellent for isolation, typically require lighter weights, which limits the ability to create substantial progressive overload. The smaller loads may restrict overall muscle fibre recruitment, particularly for those looking to maximise their gains. Although concentration curls can be progressively overloaded, the increments are smaller, and the maximal strength potential is lower compared to barbell curls.

That said, concentration curls can still be beneficial as part of a comprehensive training programme, especially when used to target specific weak points or to improve muscle symmetry.

Range of Motion and Technique

Barbell Curl Range of Motion

Barbell curls typically allow for a more standard range of motion (ROM), depending on how well the individual can control the movement and avoid momentum. One common issue with barbell curls is the tendency to “cheat” by using body sway or momentum, particularly when lifting heavier weights. This not only reduces the effectiveness of the exercise but also increases the risk of injury.

To optimise the ROM in barbell curls, maintaining strict form by keeping the elbows close to the body and avoiding excessive movement from the torso is essential. Proper form ensures that the tension remains on the biceps throughout the movement, promoting muscle growth.

Concentration Curl Range of Motion

Concentration curls generally have a more controlled and fuller range of motion due to the seated position and stabilisation of the upper arm. The isolation provided by bracing the arm against the thigh ensures that the biceps are the primary movers, which can help to develop a better peak contraction and improve mind-muscle connection.

One of the advantages of the concentration curl is the minimisation of “cheating” or momentum. Because of the braced position, it is difficult to use other muscles to assist in lifting the weight, which increases the effectiveness of the exercise for isolating the biceps.

Strength Gains vs Hypertrophy

Strength and hypertrophy (muscle size) are closely related, but they are not the same. Strength training typically focuses on lower rep ranges and higher loads, while hypertrophy benefits from moderate rep ranges and sufficient time under tension.

Barbell Curl for Strength

Barbell curls, due to their ability to accommodate heavier loads, are ideal for those looking to build strength. Studies suggest that exercises involving heavier weights and compound movements tend to be more effective for increasing overall muscle strength (Schoenfeld et al., 2014). The barbell curl allows for the kind of mechanical tension needed to stimulate significant strength gains in the biceps and forearms.

Concentration Curl for Hypertrophy

Concentration curls, with their emphasis on isolation and controlled ROM, are better suited for hypertrophy. The higher time under tension per rep and the intense focus on the biceps can lead to greater muscle growth when performed in moderate rep ranges (8-12 reps). Research by Wakahara et al. (2013) indicates that greater muscle activation, especially in isolated movements, can lead to enhanced hypertrophic outcomes.

Practical Application in Training

Both exercises have their unique benefits, but how should they be implemented in a training routine?

Using Barbell Curls

Barbell curls should be used as a primary movement for those aiming to increase both biceps size and overall upper body strength. Because they allow for heavier loads and compound activation, they can form the foundation of a biceps-focused training session. Including barbell curls early in a workout will enable you to lift the heaviest weights when your energy levels are highest.

Using Concentration Curls

Concentration curls are better suited for the latter part of a workout, after performing heavier compound lifts. As an accessory movement, they can help to further isolate the biceps and enhance the muscle pump, contributing to muscle hypertrophy. For those focusing on building a better biceps peak, concentration curls are an excellent option due to their isolation capabilities.

Conclusion: Which Is Better for Bicep Muscle Growth?

Both the barbell curl and the concentration curl offer valuable benefits depending on your goals. If your primary focus is on building overall biceps strength and size, the barbell curl is the superior choice due to its capacity for heavier loads and broader muscle recruitment. However, if you want to isolate the biceps and focus on hypertrophy, the concentration curl is more effective for maximising muscle activation and developing muscle symmetry.

The optimal approach would be to incorporate both exercises into your training routine, allowing you to take advantage of the strengths of each. Combining heavy barbell curls with lighter, more focused concentration curls provides a comprehensive stimulus for both strength and hypertrophy, ensuring balanced bicep development.

Key Takeaways Table

Bibliography

Oliveira, L.F., Matta, T.T., Alves, D.S., Garcia, M.A., Vieira, T.M.M., 2009. Electromyographic analysis of biceps brachii during elbow flexion exercises with different loads. Journal of Strength and Conditioning Research, 23(9), pp.2460-2466.