Preacher Curl vs. Incline Curl Regional Muscle Growth Summary
- The study involved 38 healthy women who completed a 9-week resistance training program. The participants were divided into two groups: one group performed inclined bicep curls, and the other performed preacher curls.
- The study found no growth differences between regions when analyzing per group. However, the preacher curl resulted in more muscle growth in the distal region of the biceps (i.e., part of the biceps muscle closest to the elbow joint).
- The study suggests that exercises that place the highest strain on the muscles when elongated (such as preacher curls) may lead to regional hypertrophy in the distal region of the arm.
Introduction to Regional Muscle Growth
Muscle growth, also known as muscle hypertrophy, is a complex process highly dependent on tension placed on the muscles. (Schoenfeld et al., 2021) Emerging evidence suggests that muscle growth does not occur evenly throughout the muscle. This phenomenon, known as regional hypertrophy, has drawn considerable attention in recent years. (Franchi et al., 2018; Matta et al., 2011)
Regional muscle growth refers to the phenomenon where different regions of a muscle experience varying degrees of hypertrophy or increase in size in response to resistance training. This means that certain parts of a muscle may grow more than others when subjected to specific exercises.
For example, Zabaleta-Korta et al. (2021) found that different exercises (i.e., smith machine squats and leg extensions) elicit different regional hypertrophy in the legs. The authors found that squats and leg extensions influenced regional hypertrophy, as it was different even if both groups had followed the same volume and intensity protocol. Squats resulted in greater increases in the vastus lateralis, whereas leg extensions increased the rectus femoris. (Zabaleta-Korta et al., 2021) This suggests that different exercises impact muscle growth in different regions.
One such area of interest is comparing preacher and incline curls, specifically focusing on their impact on regional muscle growth and hypertrophy. This article aims to comprehensively analyze the existing scientific literature on the subject, highlighting key findings and insights from a recent study titled “Regional Hypertrophy: The Effect of Exercises at Long and Short Muscle Lengths in Recreationally Trained Women,” published in the Journal of Human Kinetics by Aitor Zabaleta-Korta and colleagues. (Zabaleta-Korta et al., 2023)
The Science Behind the Dumbbell Biceps Incline Curl
The biceps, a muscle in the upper arm, comprises two heads: the long (outer) head and the short (inner) head. A 2009 study found that the incline curl resulted in greater muscular activation throughout the full range of motion than a preacher curl. The author suggested that an incline curl may be preferable for muscle hypertrophy. (Oliveira et al., 2009)
1. Adjust your workout bench to a 45-degree angle or up to 60 degrees as needed. Sit down against the, keeping your back straight and your abdominal muscles tight. Your arms should hang straight down at your sides, each hand holding a dumbbell.
2. Lift each dumbbell, palms up, toward your shoulders. It’s important to keep your upper arms tight to isolate the biceps brachii muscle as you move your lower arms only.
3. Slowly lower the dumbbell back down to your starting position. Don’t release the tension in your muscles; instead, control the movement as you lower the weights.
This elongated position of the arm muscles during the exercise may stimulate further increases in muscle size in the arm’s distal region (close to the elbow). Incline curls are performed with the shoulders extended behind the torso, emphasizing the long head of the biceps more than preacher curls.
Preacher Curl: A Closer Look
Preacher curls are performed using a preacher bench, which isolates the upper arms and prevents using momentum to cheat. This exercise primarily targets the biceps brachii, brachialis, and brachioradialis in the upper arm and forearms.
1.) Sit or stand at the preacher bench and place your upper arms on the pad. Your arms should be extended, and your palms should be facing upward. Hold the weight in your hands.
2.) Curl the weight up towards your shoulders, keeping your upper arms stationary on the pad. This movement should only involve your forearms. Ensure you maintain weight control throughout the movement, avoiding any sudden jerks or drops.
3.) Slowly lower the weight back down to the starting position, fully extending your arms but keeping a slight bend in your elbows to maintain tension in your biceps.
Many often place a barbell preacher curls over a cable preacher for bigger biceps. A 2020 study found no difference in muscle growth of the biceps performing cable and barbell preacher curls. (Nunes et al., 2020)
While both incline and preacher curls result in muscle activation, preacher curls result in greater muscle strain when the muscle is elongated, which could result in greater muscle growth of the biceps muscles closest to the elbow. (Nosaka & Sakamoto, 2001)
Incline vs. Preacher Curl: What’s Better for Muscle Growth
Researchers analyze the role of exercises (i.e., preacher curl vs. incline curls) and their effects on regional hypertrophy. The exercise protocol used in the study involved a 9-week resistance training program consisting of 4 sets of 12 repetitions of either inclined bicep curls or preacher curls, performed three times per week.
At the end of the study, both groups had similar increases in muscle size, except for the distal of the biceps. The study found that the distal region of the arm grew in response to the preacher curl, while the rest of the regions of that group and all the regions of the other group did not. This suggests that the preacher curl offers more of an advantage, although small for increasing biceps size compared to the incline dumbbell curl. This study indicates that exercises with varying resistance profiles can elicit different levels of muscle strain. Specifically, they found that exercises that placed the highest strain at specific points in the range of motion resulted in regional hypertrophy in the corresponding muscle regions.
In conclusion, both preacher and incline curls have unique benefits and impacts on regional muscle growth and hypertrophy. While preacher curls lead to more growth in the distal region of the muscle, incline curls provide a more robust hypertrophy stimulus due to the consistent resistance they provide. Therefore, incorporating both exercises into your workout routine can lead to balanced and comprehensive muscle growth. Performing these exercises with proper form and technique is essential to maximize their benefits and prevent injury.
Franchi, M. V., Ruoss, S., Valdivieso, P., Mitchell, K. W., Smith, K., Atherton, P. J., Narici, M. V., & Flück, M. (2018). Regional regulation of focal adhesion kinase after concentric and eccentric loading is related to remodelling of human skeletal muscle. Acta Physiol (Oxf), 223(3), e13056. https://doi.org/10.1111/apha.13056
Matta, T., Simão, R., de Salles, B. F., Spineti, J., & Oliveira, L. F. (2011). Strength training’s chronic effects on muscle architecture parameters of different arm sites. J Strength Cond Res, 25(6), 1711-1717. https://doi.org/10.1519/JSC.0b013e3181dba162
Nosaka, K., & Sakamoto, K. (2001). Effect of elbow joint angle on the magnitude of muscle damage to the elbow flexors. Med Sci Sports Exerc, 33(1), 22-29. https://doi.org/10.1097/00005768-200101000-00005
Nunes, J. P., Jacinto, J. L., Ribeiro, A. S., Mayhew, J. L., Nakamura, M., Capel, D. M. G., Santos, L. R., Santos, L., Cyrino, E. S., & Aguiar, A. F. (2020). Placing Greater Torque at Shorter or Longer Muscle Lengths? Effects of Cable vs. Barbell Preacher Curl Training on Muscular Strength and Hypertrophy in Young Adults. Int J Environ Res Public Health, 17(16). https://doi.org/10.3390/ijerph17165859
Oliveira, L. F., Matta, T. T., Alves, D. S., Garcia, M. A., & Vieira, T. M. (2009). Effect of the shoulder position on the biceps brachii emg in different dumbbell curls. J Sports Sci Med, 8(1), 24-29.
Schoenfeld, B. J., Grgic, J., Van Every, D. W., & Plotkin, D. L. (2021). Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum. Sports (Basel), 9(2). https://doi.org/10.3390/sports9020032
Zabaleta-Korta, A., Fernández-Peña, E., Torres-Unda, J., Francés, M., Zubillaga, A., & Santos-Concejero, J. (2023). Regional Hypertrophy: The Effect of Exercises at Long and Short Muscle Lengths in Recreationally Trained Women [journal article]. Journal of Human Kinetics, 88, 259-270. https://doi.org/10.5114/jhk/163561
Zabaleta-Korta, A., Fernández-Peña, E., Torres-Unda, J., Garbisu-Hualde, A., & Santos-Concejero, J. (2021). The role of exercise selection in regional Muscle Hypertrophy: A randomized controlled trial. J Sports Sci, 39(20), 2298-2304. https://doi.org/10.1080/02640414.2021.1929736
What are the benefits of preacher curls?
Preacher curls provide targeted isolation of the biceps brachii muscle, leading to increased strength and growth. They also help improve overall arm stability and forearm strength. Incorporating preacher curls into your workout routine can help you achieve well-defined and sculpted biceps.
In the world of bodybuilding and upper body strength training, two exercises stand out for their effectiveness in targeting the biceps: preacher curls and incline curls. Both exercises are variations of the classic biceps curl, but each offers unique benefits and challenges that can help lifters of all experience levels build stronger biceps.
The preacher curl is a simple movement that provides a deep dive into biceps training. It is performed on a preacher curl bench, with the lifter using an underhand grip on an EZ bar or free weights. The lifter’s upper arms rest on the bench, isolating the biceps and forearms and preventing the use of momentum or cheating the curl movement. This isolation exercise forces the biceps to work harder, leading to maximum gains.
The preacher curl machine or bench setup is crucial to maintain perfect form and preventing lower back strain. The lifter’s armpits should be snug against the top of the bench, and the EZ curl bar or dumbbells should be gripped with a close grip for the classic preacher curl. The lifter performs reps, curling the weights up and down in a controlled manner. The top of the curl is the strongest grip point, and the lifter should focus on maintaining tension in the biceps throughout the movement.
Benefits of Preacher Curls
The benefits of the preacher curl are numerous. It is a more natural movement pattern that reduces stress on the shoulder joint and rotator cuff compared to other biceps exercises. It also targets the short head of the biceps, contributing to upper body strength and bodybuilding aesthetics. However, lighter weights are recommended for beginners, as the isolated nature of the exercise can be challenging.
On the other hand, incline curls are performed on an incline bench, with the lifter’s arms hanging down and the weights curled up. This exercise targets the long head of the biceps, which forms the biceps peak. The incline position stretches the long head, allowing it to contract with more force and thus take on the majority of the load during the exercise. This makes incline curls an effective exercise for building the biceps peak.
Both exercises can be performed with different angles and grip to target different parts of the biceps. For example, an overhand grip can be used for a variation of the preacher curl, while different incline angles can be used for incline curls. Regardless of the variation, maintaining proper form and control throughout the movement is the only way to ensure safety and effectiveness.
In conclusion, preacher and incline curls are effective exercises for arms training and building stronger biceps. They offer different benefits and challenges, making them suitable for lifters of all experience levels. By incorporating these exercises into their training regimen, lifters can enjoy a variety of biceps curl variations and experience the benefits of these exercises firsthand.