摘要
AthleanX 的 Jeff Cavaliere 认为，夹胸飞鸟动作在很大程度上是一个低效且潜在危险的胸部训练动作。他用橡皮筋来演示肌肉纤维的走向，解释说在飞鸟动作最低点感受到的拉伸来自喙肱肌，而非胸大肌。他承诺将发布后续视频，展示如何仅用平板凳来训练上胸。
核心要点
- 夹胸飞鸟被认为是浪费时间的动作，尽管在以胸部发展为目标的健身者中被广泛使用，但对胸大肌的增肌效果甚微。
- 胸大肌起点沿胸骨分布，止点位于上臂骨（肱骨）外侧；其肌肉纤维横向贯穿胸部。
- 在飞鸟动作过程中，胸大肌起点与止点之间的相对距离与卧推相比并无显著变化——这意味着胸肌并未获得额外的有效拉伸。
- 在飞鸟动作最低点感受到的深度拉伸，实际上是喙肱肌承受张力的体现，该肌肉从肩部深处的喙突延伸至上臂——而非来自胸大肌。
- 由于被加载的是喙肱肌而非胸肌，夹胸飞鸟并不能提供更出色的胸肌激活效果，尽管动作感觉更为强烈。
- 飞鸟动作幅度过大会增加肩部受伤的风险，包括胸肌撕裂和肩锁关节损伤，却无法带来额外的胸部发展收益。
- 推荐所有推举类动作作为更有效、更安全的胸部训练选择。
动作详情
夹胸飞鸟
- 目标肌肉（预期）： 胸大肌
- 实际主要拉伸部位： 喙肱肌（而非胸大肌）
- 常见错误：
- 误以为更大的活动幅度能增加 pec muscle stretch——实际上并非如此
- 将手臂下放超过身体自然平面，在对胸部发展毫无益处的情况下增加肩关节压力
- 将飞鸟作为主要的胸部增肌动作
- 建议： 不建议用于胸部训练目的；该动作存在受伤风险，却对胸部针对性刺激极为有限
卧推（作为对比参考）
- 目标肌肉： 胸大肌
- 动作要点：
- 不要将杠铃下放超过胸部平面，以避免肩关节压力过大
- 在整个推举过程中，胸大肌起止点关系能得到适当的负荷
- 建议： 在 chest hypertrophy 方面优于飞鸟动作
相关概念
- chest hypertrophy
- pec major
- muscle origin and insertion
- range of motion
- shoulder injury prevention
- pressing movements
- functional training
English Original 英文原文
Summary
Jeff Cavaliere of AthleanX argues that the chest fly is a largely ineffective and potentially dangerous exercise for chest development. Using a rubber band to illustrate muscle fiber direction, he explains that the stretch felt at the bottom of a fly movement comes from the coracobrachialis, not the pec major. He promises a follow-up video showing how to train the upper chest using only a flat bench.
Key Points
- The chest fly is considered a waste of time for building the pec major, despite being widely used by gym-goers focused on chest development.
- The pec major originates along the sternum and inserts at the outer portion of the upper arm bone (humerus); its fibers run horizontally across the chest.
- During a fly movement, the relative distance between the pec major’s origin and insertion does not change significantly compared to a bench press — meaning no meaningful additional stretch is placed on the chest muscle.
- The deep stretch felt at the bottom of a fly is actually tension on the coracobrachialis, a muscle running from the coracoid process (deep in the shoulder) down to the upper arm — not the pec major.
- Because the coracobrachialis is being loaded — not the pec — the chest fly does not provide superior chest activation despite feeling more intense.
- Going deep into a fly position increases the risk of shoulder injury, including pec tears and AC joint damage, without delivering added chest development in return.
- All pressing movements are recommended as the more effective and safer choice for building the chest.
Exercise Details
Chest Fly
- Target muscles (intended): Pec major
- Actual primary stretch: Coracobrachialis (not the pec major)
- Common mistakes to avoid:
- Assuming a deeper range of motion increases pec muscle stretch — it does not
- Lowering arms below the body’s natural plane, which stresses the shoulder joint without benefit to chest development
- Using the fly as a primary chest-building movement
- Recommendation: Avoid for chest development purposes; the exercise creates injury risk with minimal chest-specific stimulus
Bench Press (referenced for comparison)
- Target muscles: Pec major
- Form cues:
- Do not lower the bar below the chest plane to avoid shoulder joint stress
- The pec major’s origin-to-insertion relationship is appropriately loaded throughout the press movement
- Recommendation: Preferred over flies for chest hypertrophy
Mentioned Concepts
- chest hypertrophy
- pec major
- muscle origin and insertion
- range of motion
- shoulder injury prevention
- pressing movements
- functional training