Cable vs. Dumbbell Curls: Which Builds Bigger Biceps Faster?

Building bigger biceps is a primary goal for many gym-goers. The debate between cable curls and dumbbell curls has persisted for years, with proponents on both sides. Which exercise leads to faster hypertrophy?

To determine the answer, we must delve into biomechanics, muscle activation, resistance profiles, and peer-reviewed research.

Understanding Biceps Anatomy

The biceps brachii consists of two heads: the short head and the long head. Both originate from the scapula and insert into the radius. The primary functions of the biceps are elbow flexion and forearm supination.

Effective biceps exercises must place tension on these functions throughout a range of motion. A study by Narici et al. (1996) demonstrated that muscle growth occurs most effectively when training involves mechanical tension, metabolic stress, and muscle damage.

Dumbbell Curls: Strengths and Limitations

Dumbbell curls are a staple in arm training. They involve lifting a weight against gravity, with resistance peaking at the mid-range of the motion when the forearm is perpendicular to the ground. This means that tension is highest halfway through the curl and reduces at the top and bottom of the movement.

Benefits of Dumbbell Curls

1. Freedom of Movement: Dumbbells allow a natural range of motion. You can supinate the forearm during the curl, engaging the biceps more effectively (Schoenfeld, 2010).
2. Bilateral and Unilateral Training: You can train each arm independently, which can correct muscle imbalances.
3. Stabilizer Muscle Activation: Dumbbells require stabilization, leading to secondary muscle engagement, including the brachialis and brachioradialis (Ogasawara et al., 2013).

Limitations of Dumbbell Curls

1. Inconsistent Tension: Gravity-based resistance drops at the bottom and top of the movement.
2. Momentum Usage: It is easier to cheat by swinging the dumbbells, reducing muscle activation.
3. Joint Strain: In poorly controlled curls, excessive wrist and elbow strain can occur.

Cable Curls: Strengths and Limitations

Cable curls involve a cable pulley system that provides constant resistance throughout the range of motion. Tension does not vary based on joint angle or gravity but remains consistent, depending on the direction of the cable relative to the limb.

Benefits of Cable Curls

1. Constant Tension: Cables maintain muscle tension throughout the entire range, even at the bottom and top of the curl (McMaster et al., 2009).
2. Variable Angles: You can manipulate the angle of resistance to target different parts of the biceps.
3. Reduced Momentum: The pulley system resists sudden acceleration, minimizing the chance to cheat.
4. Joint-Friendly: Smooth resistance reduces joint compression and shear forces.

Limitations of Cable Curls

1. Less Stabilizer Engagement: The guided path of the cable reduces the need for stabilizing muscles.
2. Equipment Dependency: Requires a cable machine, which may not always be available.
3. Setup Complexity: Adjusting angles and handles requires more knowledge and setup time.

Muscle Activation and EMG Studies

To compare muscle activation, we turn to electromyographic (EMG) analysis. A study by Signorile et al. (2002) compared EMG activity in various biceps exercises. Cable curls showed more consistent activation across the range of motion. In contrast, dumbbell curls showed peak activation mid-range and decreased activity at the endpoints.

Another study by Oliveira et al. (2009) confirmed that the long head of the biceps is more active during incline dumbbell curls, whereas cable curls showed greater overall activation due to consistent loading.

Resistance Profile and Muscle Growth

The resistance profile of an exercise impacts hypertrophy. Dumbbell curls provide an ascending resistance curve, meaning resistance is harder mid-rep. Cable curls can be adjusted to match the strength curve of the biceps more effectively.

Research by Wakahara et al. (2012) demonstrated that constant mechanical tension, as seen in cable training, leads to more significant muscle protein synthesis and hypertrophic response.

Time Under Tension (TUT)

Time under tension plays a pivotal role in muscle growth. Cable curls inherently increase TUT due to constant resistance. A study by Burd et al. (2012) found that longer durations under tension led to greater muscle protein synthesis compared to shorter bursts of high intensity.

With dumbbells, TUT varies. At the top and bottom of the curl, muscles are minimally loaded, reducing the effectiveness unless the lifter intentionally slows the rep speed.

Range of Motion (ROM) Considerations

Both exercises allow full elbow flexion and extension, but cable machines can provide better tension at full stretch and contraction. This matters because studies, such as the one by Schoenfeld et al. (2014), have shown that training muscles through a full ROM maximizes hypertrophy.

Progressive Overload and Load Management

Dumbbells typically allow for easier progressive overload, as gyms offer incremental weight increases. Cable stacks may have larger jumps between plates, making fine-tuned progression trickier. However, cables offer better load control due to smoother mechanics, allowing for precise tempo training.

Practical Applications for Program Design

For hypertrophy, combining both exercises may be optimal. Begin workouts with dumbbell curls to utilize maximal stabilizer recruitment when fresh, followed by cable curls to accumulate metabolic stress and TUT.

A sample biceps routine:

• Incline Dumbbell Curl: 3×10 (emphasizes long head)
• Standing Alternating Dumbbell Curl: 3×8 (mid-range strength)
• Cable Curl with Bar: 3×12 (constant tension)
• Overhead Cable Curl: 3×15 (peak contraction focus)

Real-World Application in Athletic and Aesthetic Training

Athletes benefit from functional dumbbell curls for joint control and coordination, while bodybuilders may prefer cables for peak contraction and muscle isolation. The goal dictates the choice: for mass, consistency, and maximal time under tension, cables win. For general strength and balance, dumbbells provide a versatile tool.

Conclusion

In isolation, cable curls build bigger biceps faster due to superior time under tension, consistent mechanical load, and adjustable resistance profiles. EMG studies and hypertrophy research support their efficacy. However, dumbbell curls offer benefits in motor control, stabilizer activation, and practical loading. For maximal growth, incorporating both is ideal, leveraging each tool’s strengths throughout a training cycle.

References

Burd, N.A., Andrews, R.J., West, D.W.D., Little, J.P., Cochran, A.J.R., Hector, A.J., Cashaback, J.G.A., Gibala, M.J., Potvin, J.R. and Phillips, S.M., 2012. Muscle time under tension during resistance exercise stimulates differential muscle protein sub-fractional synthetic responses in men. Journal of Physiology, 590(2), pp.351-362.

McMaster, D.T., Gill, N.D., Cronin, J.B. and McGuigan, M.R., 2009. A brief review of strength and ballistic assessment methodologies in sport. Sports Medicine, 39(11), pp.979-990.

Narici, M.V., Hoppeler, H., Kayser, B., Landoni, L., Claassen, H., Gavardi, C., Conti, M. and Cerretelli, P., 1996. Human quadriceps cross-sectional area, torque and neural activation during 6 months strength training. Acta Physiologica Scandinavica, 157(2), pp.175-186.

Ogasawara, R., Loenneke, J.P., Thiebaud, R.S. and Abe, T., 2013. Low-load bench press training to fatigue results in muscle hypertrophy similar to high-load bench press training. International Journal of Clinical Medicine, 4(02), pp.114-121.

Oliveira, L.F., Matta, T.T., Alves, D.S., Garcia, M.A. and Vieira, T.M., 2009. Effect of the shoulder position on the biceps brachii EMG in different dumbbell curls. Journal of Sports Science and Medicine, 8(1), p.24.

Schoenfeld, B.J., 2010. The mechanisms of muscle hypertrophy and their application to resistance training. Journal of Strength and Conditioning Research, 24(10), pp.2857-2872.

Schoenfeld, B.J., Grgic, J., Ogborn, D. and Krieger, J.W., 2014. Strength and hypertrophy adaptations between low- vs. high-load resistance training: a meta-analysis. Journal of Strength and Conditioning Research, 31(12), pp.3508-3523.

Signorile, J.F., Zink, A.J. and Szwed, S., 2002. A comparative electromyographical investigation of muscle utilization patterns using various hand positions during the lat pull-down. Journal of Strength and Conditioning Research, 16(4), pp.539-546.

Wakahara, T., Fukutani, A., Kawakami, Y. and Yanai, T., 2012. Nonuniform muscle hypertrophy: its relation to muscle activation in training session. Medicine & Science in Sports & Exercise, 44(6), pp.1120-1127.