The biceps are a two-headed muscle on the upper arm. Per StatPearls, “the long head originates from the supraglenoid tubercle of the scapula. The short head originates from the coracoid process of the scapula.” (1)
The biceps flex the elbow, supinate the forearm, and assist shoulder flexion and abduction. (2) Elbow flexor muscle size (i.e., biceps) was the focus of a 2025 Journal of Sports Medicine study that compared preacher and incline biceps curls for strength and hypertrophy and suggested that including both in a training program is best for overall biceps size and strength. (3) Discover the study’s findings below to understand why.
Study’s Significant Observations
- “Greater increase in the proximal elbow flexor thickness in the incline biceps curl compared to the preacher biceps curl.”
The proximal elbow flexor is closer to the shoulder, meaning that incline biceps curls help build thickness in the upper region of the biceps.
- “Greater increase in the distal elbow flexor thickness in the preacher biceps curl compared to the incline biceps curl.”
The distal elbow flexor is closer to the elbow, meaning that preacher curls help build thickness in the lower region of the biceps.
- Suggested “regional differences in muscle growth induced by the preacher and incline biceps curls.”
The upper and lower regions of the biceps respond to different types of curls, suggesting that applying preacher curls and incline biceps curls into one’s training program is more optimal than only including one or the other.
- “Strength gains appear to follow the principle of specificity.”
Isolation training is effective for gaining strength in the targeted muscle group.
How to Incline Biceps Curl
Here is an easy step-by-step guide to perform incline biceps curls with an adjustable weight bench and a pair of dumbbells:
- Set an adjustable weight bench at a 45 to 65-degree angle relative to the floor.
- Sit and allow the dumbbells to hang in your grip naturally at your sides so they are perpendicular to the floor.
- Keep your elbows back and your arms behind your torso we you curl.
- Cue: try to curl your wrist to the mid-biceps.
How to Preacher Curl
Here is an easy step-by-step guide to perform preacher curls:
- Adjust the preacher curl bench height so that the chest can contact it while being flush on the triceps.
- Drive the triceps into the pad as you curl with a tight grip to improve shoulder stability.
- Reverse the curl to the starting position without releasing any of the tension in the pad or tightness of the grip.
More Training Content
- 3 Reasons Why Upright Rows Are Bad
- Your Upper Chest Isn’t Growing Because You’re Pressing at the Wrong Angle
- When Should You Increase Weight on the Barbell?
References
- Tiwana MS, Charlick M, Varacallo MA. Anatomy, Shoulder and Upper Limb, Biceps Muscle. [Updated 2024 Jan 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519538/
- “Biceps Muscle.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., www.britannica.com/science/biceps-muscle. Accessed 02 July 2025.
- Kassiano, W., et al. International Journal of Sports Medicine, vol. 46, no. 05, 14 Jan. 2025, pp. 334-343, doi:10.1055/a-2517-0509
Featured image via Shutterstock/nazarovsergey
