Uploaded January 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 due to its muscle fiber 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 due to its muscle fiber 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! 👇💬
