Concentric Exercise: Definition, Examples, and Importance

What is an example of a concentric exercise?

A concentric exercise involves a muscle shortening under tension as it overcomes a resistance, leading to movement. A classic example is the upward phase of a bicep curl, where the biceps brachii muscle shortens to lift the weight towards the shoulder.

Understanding Muscle Contraction: The Basics

To grasp the concept of a concentric exercise, it's essential to understand the three primary types of muscle contraction that occur during movement:

• Concentric Contraction: The muscle shortens while generating force, causing movement. This is the lifting or "positive" phase of an exercise.
• Eccentric Contraction: The muscle lengthens under tension, often while resisting gravity or an external force. This is the lowering or "negative" phase, acting as a brake.
• Isometric Contraction: The muscle generates force without changing length. This occurs when holding a position against resistance, such as holding a plank or pausing at the bottom of a squat.

Each type of contraction plays a crucial role in human movement, strength development, and injury prevention.

What is Concentric Contraction?

Concentric contraction is the most commonly recognized form of muscle action, as it directly results in the visible movement of limbs and joints against resistance. During a concentric contraction:

• Muscle Shortening: The muscle fibers pull closer together. This occurs as the actin and myosin filaments within the muscle cells slide past each other, a process explained by the sliding filament theory.
• Force Generation: The muscle produces enough force to overcome the external load or resistance. If the force generated by the muscle is greater than the resistance, the muscle shortens and movement occurs.
• Work Performed: Concentric contractions are responsible for the "lifting" or "pushing" actions in exercises and daily activities. They are crucial for accelerating body segments and external objects.

Think of any movement where you are actively lifting, pushing, or pulling an object – the muscles involved are primarily undergoing concentric contraction.

The Concentric Phase in Action: A Practical Example

A highly illustrative example of a concentric exercise, or more accurately, the concentric phase of an exercise, is the Bicep Curl.

Let's break down the concentric phase of a standard dumbbell bicep curl:

1. Starting Position: You begin with a dumbbell held in your hand, arm extended downwards, palm facing forward. Your biceps brachii muscle is in a lengthened position.
2. The Concentric Action: As you initiate the curl, you actively bend your elbow, bringing the dumbbell upwards towards your shoulder.
   • During this upward movement, your biceps brachii muscle (the primary mover or agonist) shortens under tension. It is generating force sufficient to lift the dumbbell against gravity.
   • The muscle fibers of the biceps contract, causing the forearm to flex at the elbow joint.
3. Peak Contraction: The concentric phase concludes when the dumbbell reaches its highest point, typically near your shoulder, and the biceps is maximally shortened.

Conversely, the lowering of the dumbbell back to the starting position would be the eccentric phase, where the biceps lengthens under control.

Other examples of concentric phases in common exercises include:

• Squat: The upward movement from the bottom position to standing. (Quadriceps, glutes, adductors shorten)
• Push-up: Pushing your body up from the floor to full arm extension. (Pectorals, triceps, anterior deltoids shorten)
• Bench Press: Pressing the barbell upwards from your chest. (Pectorals, triceps, anterior deltoids shorten)
• Row: Pulling the weight towards your torso. (Latissimus dorsi, rhomboids, biceps shorten)

Why Concentric Training Matters

Concentric training is fundamental for developing a wide range of physical attributes:

• Strength Development: It is the primary mechanism for increasing the maximum force a muscle can produce.
• Power Output: Concentric contractions, especially when performed rapidly, are essential for explosive movements seen in sports like jumping, throwing, and sprinting.
• Muscle Hypertrophy: The tension and metabolic stress generated during concentric work contribute significantly to muscle growth.
• Functional Movement: Most daily activities, from lifting a grocery bag to climbing stairs, heavily rely on concentric muscle actions.

Integrating Concentric Training into Your Routine

When performing exercises, consciously focusing on the concentric phase can enhance your mind-muscle connection and ensure effective training. While the eccentric phase is also critically important for strength and hypertrophy, understanding and emphasizing the concentric "lift" or "push" ensures you are actively engaging the target muscles to overcome resistance. Proper form, controlled movement, and progressive overload are key to maximizing the benefits of concentric training.

Conclusion

A concentric exercise, exemplified clearly by the upward phase of a bicep curl, is characterized by a muscle shortening as it generates force to move a load. This fundamental type of muscle contraction is at the heart of most dynamic movements, contributing significantly to strength, power, and muscle development, making it a cornerstone of any effective fitness regimen.