Shoulder-extended curls may slightly favor biceps growth, especially in upper regions.
Original: Bigger Biceps: This NEW Study Is Interesting
TL;DR
The evidence shows mixed support for shoulder-extended curls being superior to preacher curls for biceps growth, with some studies favoring incline curls for upper biceps development while others show no difference.
Quick Answer
The new study compared shoulder-extended cable curls (like Bayesian curls) and shoulder-flexed preacher curls, matching resistance profiles, and found no statistically significant difference in biceps growth after 10 weeks of training. However, numerical trends favored Bayesian curls for upper biceps growth and preacher curls for brachiialis development. When combined with existing research—especially studies on incline curls showing superior biceps growth at 20–50% length—it suggests shoulder-extended curls may slightly outperform preacher curls for biceps hypertrophy, particularly in the upper regions.
Claims (10)
1. Just because a study doesn’t find a clear difference in arm muscle growth between two curl types, it doesn’t mean there isn’t a real difference — the study might just be too small to catch it.
2. When you move your arm backward, it stretches your biceps because the muscle runs over your shoulder joint — and when you move your arm forward, the biceps gets shorter.
3. Working your biceps with your arms stretched back might grow the upper part of the muscle a bit more than doing curls with your arms already in front of you.
4. Doing bicep curls on an incline bench builds more muscle in the upper part of your biceps than preacher curls do.
5. Doing preacher curls might build more muscle in a specific lower part of your upper arm than incline curls do.
6. Doing bicep curls on an incline bench might build your biceps muscle better than doing preacher curls, especially in the middle part of your upper arm.
7. Small studies might miss real differences just because they don’t have enough people in them — it’s like trying to hear a whisper in a noisy room.
8. If you mix up your workouts for the same muscle, you’ll grow that muscle more evenly than if you always do the same exercise.
9. If you stretch your hips back while doing leg extensions, your quad muscle gets longer and grows more—especially in the middle and upper parts—than if you do the exercise with your hips bent.
10. If you do leg extensions while leaning back, it might build more muscle in the top part of your front thigh compared to doing them upright.
Key Takeaways
- •Problem: It's unclear which biceps exercise—preacher curls or shoulder-extended curls like incline or Bayesian curls—is best for building bigger arms.
- •Core methods: Shoulder-extended curls (e.g., incline dumbbell curls, Bayesian cable curls), preacher curls (shoulder-flexed position), resistance profile matching, regional muscle measurement, and comparison across multiple studies.
- •How methods work: Shoulder-extended curls stretch the biceps more because the arm is behind the body, which may help it grow better, especially in the upper part. Preacher curls shorten the biceps and may better target the brachiialis. Matching resistance ensures fair comparison, and measuring different muscle regions shows where growth happens.
- •Expected outcomes: Shoulder-extended curls may lead to slightly more biceps growth, especially in the upper portion, while preacher curls may better develop the brachiialis and brachioradialis. Overall, both work, but extended-position curls might have a small edge.
- •Implementation timeframe: Results observed after 8–10 weeks of consistent training, 2–3 times per week with 3–5 sets of 8–12 reps to near failure.
Overview
The central problem is identifying the most effective biceps isolation exercise for maximizing hypertrophy, particularly whether shoulder position (extended vs. flexed) influences growth. The solution evaluated in this video centers on a new study comparing Bayesian cable curls (shoulder extended) and preacher curls (shoulder flexed) with matched resistance profiles, supplemented by analysis of incline curl studies and cross-muscle evidence. The core methods include resistance training with bi-articular positioning, regional muscle thickness assessment, and meta-level interpretation of statistical trends and comparative literature to infer practical implications for biceps development.
Key Terms
How to Apply
- 1.Step 1: Perform biceps training 2–3 times per week using 3–5 sets of 8–12 repetitions taken to or very close to muscular failure.
- 2.Step 2: Include shoulder-extended biceps exercises such as incline dumbbell curls or Bayesian cable curls, ensuring the shoulder is in extension (arm behind the torso) during the movement.
- 3.Step 3: Optionally include preacher curls to target the brachiialis and brachioradialis, or rotate between shoulder-extended and shoulder-flexed curls to ensure balanced elbow flexor development.
- 4.Step 4: If using cable curls, adjust the cable setup so resistance is matched across exercises—ideally peaking around 60° of elbow flexion—to allow fair comparison or consistent training stimulus.
- 5.Step 5: Track progress over 8–10 weeks using consistent form, progressive overload, and consider using ultrasound or circumference measurements to assess regional muscle growth if possible.
Following these steps should result in measurable biceps hypertrophy, with a potential slight advantage in upper biceps development when prioritizing shoulder-extended curls like incline or Bayesian curls, while maintaining balanced elbow flexor growth through exercise variation.
Studies from Description (6)
Claims (10)
1. Just because a study doesn’t find a clear difference in arm muscle growth between two curl types, it doesn’t mean there isn’t a real difference — the study might just be too small to catch it.
2. When you move your arm backward, it stretches your biceps because the muscle runs over your shoulder joint — and when you move your arm forward, the biceps gets shorter.
3. Working your biceps with your arms stretched back might grow the upper part of the muscle a bit more than doing curls with your arms already in front of you.
4. Doing bicep curls on an incline bench builds more muscle in the upper part of your biceps than preacher curls do.
5. Doing preacher curls might build more muscle in a specific lower part of your upper arm than incline curls do.
6. Doing bicep curls on an incline bench might build your biceps muscle better than doing preacher curls, especially in the middle part of your upper arm.
7. Small studies might miss real differences just because they don’t have enough people in them — it’s like trying to hear a whisper in a noisy room.
8. If you mix up your workouts for the same muscle, you’ll grow that muscle more evenly than if you always do the same exercise.
9. If you stretch your hips back while doing leg extensions, your quad muscle gets longer and grows more—especially in the middle and upper parts—than if you do the exercise with your hips bent.
10. If you do leg extensions while leaning back, it might build more muscle in the top part of your front thigh compared to doing them upright.
Related Content
Claims (10)
When you move your arm backward, it stretches your biceps because the muscle runs over your shoulder joint — and when you move your arm forward, the biceps gets shorter.
Working your biceps with your arms stretched back might grow the upper part of the muscle a bit more than doing curls with your arms already in front of you.
If you do leg extensions while leaning back, it might build more muscle in the top part of your front thigh compared to doing them upright.
Doing bicep curls on an incline bench builds more muscle in the upper part of your biceps than preacher curls do.
Just because a study doesn’t find a clear difference in arm muscle growth between two curl types, it doesn’t mean there isn’t a real difference — the study might just be too small to catch it.
Studies (6)
Comparison Between Shoulder Flexed and Extended Positions in Elbow Flexion Resistance Training on Regional Hypertrophy and Maximum Strength: Preacher versus Bayesian Cable Curls
DOI: 10.1002/ejsc.12279
Distinct muscle growth and strength adaptations after preacher and incline biceps curls
DOI: 10.1055/a-2517-0509
Similar Regional Hypertrophy of the Elbow Flexor Muscles in Response to Low-Load Training With Vascular Occlusion at Short Versus Long Muscle Lengths
DOI: 10.1177/19417381241287522
Regional Hypertrophy: The Effect of Exercises at Long and Short Muscle Lengths in Recreationally Trained Women
DOI: 10.5114/jhk/163561
Does Performing Different Resistance Exercises for the Same Muscle Group Induce Non-homogeneous Hypertrophy?
DOI: 10.1055/a-1308-3674