Can’t Do Pull-Ups? The Real Reason Why
Summary
Many people struggle with pull-ups despite being able to perform chin-ups more easily. According to Jeff Cavaliere of Athlean-X, the real culprit is often a weakness in the brachioradialis — a forearm muscle that plays a critical role in the pronated (overhand) grip position used in pull-ups. Targeting this overlooked muscle directly can lead to significant improvements in pull-up performance.
Key Points
- The pull-up vs. chin-up gap is a clue: If you can do significantly more chin-ups than pull-ups, your back is likely not the limiting factor — your arm is.
- The brachioradialis is the hidden weakness: This muscle runs from the upper arm down across the forearm and is most active during elbow flexion in a pronated (overhand) grip — exactly the position used in pull-ups.
- Chin-ups remove the brachioradialis contribution: Flipping to an underhand grip shifts the load away from the brachioradialis, which is why chin-ups feel easier for many people.
- The best way to improve pull-ups is to do pull-ups: Using a resistance band looped over the bar reduces bodyweight load, allowing you to practice the movement pattern while building the required muscles.
- Direct brachioradialis training fills the gap: Supplementing pull-up practice with targeted arm exercises can accelerate progress.
- Nothing in your training should be overlooked: Weaknesses in smaller, less visible muscles are just as capable of limiting performance as weaknesses in major muscle groups.
Exercise Details
Pull-Up (with Band Assistance)
- Target muscles: Back, brachioradialis, biceps
- Form cues: Use a pronated (overhand) grip; loop a resistance band over the bar to reduce effective bodyweight
- Common mistakes: Defaulting entirely to chin-ups and never addressing the pronated-grip weakness
Reverse Curl
- Target muscles: Brachioradialis, biceps
- Form cues: Hold the bar or dumbbells with an overhand (pronated) grip and curl upward, maintaining that grip throughout
- Common mistakes: Defaulting to standard supinated bicep curls, which underload the brachioradialis
Hammer Curl (Standard & Eccentric Variation)
- Target muscles: Brachioradialis, brachialis
- Form cues:
- Neutral grip — thumb in line with the forearm
- Curl straight up and down
- Advanced variation: Supinate on the way up, then pronate slowly on the way down to emphasize the eccentric phase through the brachioradialis
- Common mistakes: Skipping the pronation on the descent, which removes the key training stimulus