Concentric Contraction
Concentric Muscle Contraction: A type of muscle contraction in which activation of motor units and the production of force results in joint motion and the shortening of the muscle. This occurs when the force produced by the muscle is greater than the external resistance. Functionally, concentric contraction can be thought of as actions that accelerate the body or a body segment, overcoming resistance.
- Etymology: The word is formed from two parts: "con" (together) and "centric" (center). Shortening could be considered as bringing parts together or, perhaps, toward the center.
Key Characteristics:
- Muscle fibers shorten while generating tension.
- Produces acceleration in opposition to the external resistance (e.g., lifting a weight).
Contraction Types:
- Shortening Contraction: Concentric contraction
- Same-length Contraction: Isometric contraction
- Lengthening Contraction: Eccentric contraction
Additional Resources:
- Related Course: Lesson 3: Joint Actions
- Related Course: Acute Variables: Repetition Tempo
- Related Article: The Best Weight Lifting Tempo: Maximum Velocity Concentrics
Examples of Concentric Contractions:
- Biceps Curl (Upward Phase): The biceps brachii contract concentrically and shorten to flex the elbow and lift the load
- Squat (Upward Phase): The gluteus maximus and quadriceps contract and shorten to extend the hip and knee and lift the load.
- Push-Up (Upward Phase): The pectoralis major and triceps brachii contract concentrically to horizontally adduct the shoulder, extend the elbows, and lift the body.
- Dumbell Chest Press (Upward Phase): The pectoralis major and triceps brachii contract concentrically to horizontally adduct the shoulder, extend the elbow, and lift the load.
- Seated Row (Pulling/Backward Phase): The latissimus dorsi and biceps brachii contract concentrically and shorten to extend the shoulder, flex the elbow, and pull the handle closer to the body.
- Lat Pull Downs (Downward Phase): The latissimus dorsi and biceps brachii contract concentrically and shorten to adduct the shoulder, flex the elbow, and pull the handle closer to the body.
- Reverse Flye/Horizontal Abduction (Backward Phase): The posterior deltoids concentrically contract and short to horizontally abduct the shoulder and pull the resistance back.
- Jumping (Upward Phase): The gluteus maximus and quadriceps contract and shorten to extend the hip and knee and lift the load.
- Kettle Bell Swing (Upward Phase): The gluteus maximus and quadriceps contract and shorten to extend the hip and knee, and the anterior deltoid concentrically contracts and shortens to flex the shoulder.
An Example of "Concentric Contraction" Used in Practice:
- Cited from the course Acute Variables: Repetition Tempo , and the article The Best Weight Lifting Tempo: Maximum Velocity Concentrics .
Tempo Notation and Recommendations
Repetition (rep) tempos are generally notated in the following format "(3:1:2)". The numbers are seconds (sec.) unless otherwise indicated. Each number corresponds to a phase of contraction in the following order: "eccentric: isometric: concentric." For Example, a pull-up with a 4:1:2 tempo would be performed with the following cadence: 2 seconds on the way up, 1-second hold at the top, and 4 seconds on the way down.
- Slow Tempo: 5 sec. or more per rep (e.g. 3:1:2)
- Moderate Tempo: 2 - 4 sec. per rep (e.g. 2:1:1)
- Fast tempo: 2 sec. or less per rep (e.g. 1:0:1)
- Maximum Voluntary Concentric Tempo (MaxV): A maximum velocity concentric contraction that does not include a quick pre-stretch, the intent to throw an object, or the intent to leave the ground (e.g. the fastest concentric contraction that can be achieved during a bench press or squat). These tempos are as fast as the load can be lifted, but are distinct from the explosive tempos used during power exercises.
- Explosive: A maximal velocity rep that includes a quick pre-stretch, shortest possible amortization phase (isometric), and the intent to release an object or leave the ground during the concentric contraction.
- +: indicates "or longer"
Brookbush Institute's Evidence-based Tempo Recommendations:
- Activation Exercises: 2-4: 2-4: MaxV or explosive
- Endurance: 2+: 0-2: MaxV or longer
- Hypertrophy: 2+: 0-2: MaxV or longer
- Functional Strength: 2+: 0-2: MaxV
- Max Strength: lifter's preference: 0: MaxV (load)
- Power: Explosive: 0: Explosive (speed) - Explosive tempos include a quick pre-stretch, the shortest amortization phase possible, and a concentric contraction with the intent to release an object or leave the ground.