Uploaded May 2026 | Updated September 2026, 2 weeks ago
Long-held theories have held that training the biceps in a lengthened position (like the Bayesian curl) leads to greater hypertrophy than a shortened position (like the preacher curl), as seen in other muscles like the hamstrings.
But a 2025 study by Attarieh et al. put this to the test! 🔬
👨🔬 What did they test?
Researchers compared the two exercises with identical resistance profiles but different shoulder positions:
✅ Preacher Curl – Biceps shortened
✅ Bayesian Curl – Biceps lengthened
📊 The results:
🔸 Both exercises led to similar gains in muscle size and strength.
🔸 No added benefit was found for training at longer muscle lengths.
🔸 No regional hypertrophy differences in the biceps.
⚖️ What does this mean?
The study suggests that the biceps may not benefit from training in a lengthened position, given its fiber-type characteristics. Since both exercises led to similar hypertrophy and strength gains, you can choose either based on comfort and preference, without worrying about missing out on results.
📣 Which one do you prefer, preacher or Bayesian?
Let us know in the comments! 👇💬
Long-held theories have held that training the biceps in a lengthened position (like the Bayesian curl) leads to greater hypertrophy than a shortened position (like the preacher curl), as seen in other muscles like the hamstrings.
But a 2025 study by Attarieh et al. put this to the test! 🔬
👨🔬 What did they test?
Researchers compared the two exercises with identical resistance profiles but different shoulder positions:
✅ Preacher Curl – Biceps shortened
✅ Bayesian Curl – Biceps lengthened
📊 The results:
🔸 Both exercises led to similar gains in muscle size and strength.
🔸 No added benefit was found for training at longer muscle lengths.
🔸 No regional hypertrophy differences in the biceps.
⚖️ What does this mean?
The study suggests that the biceps may not benefit from training in a lengthened position, given its fiber-type characteristics. Since both exercises led to similar hypertrophy and strength gains, you can choose either based on comfort and preference, without worrying about missing out on results.
📣 Which one do you prefer, preacher or Bayesian?
Let us know in the comments! 👇💬
