Concentric phase

The concentric phase, or positive phase, of an exercise is the part of a movement where the muscle is contracting and typically shortening as it works against the resistance or weight. It is commonly the phase where the most effort is required.For example:

  • In a bicep curl, the positive phase is when you lift the weight upward, contracting your biceps to bring the dumbbell toward your shoulder.
  • In a bench press, the positive phase occurs when you push the barbell away from your chest, engaging your chest, shoulders, and triceps.
  • In a squat, the positive phase is when you stand back up from the lowered position, using your leg and glute muscles to extend your hips and knees.

The positive phase is often contrasted with the negative phase (eccentric phase), where the muscle elongates under tension, such as when lowering the weight back down in a controlled manner.

Key Points about the Positive Phase:

  • Muscle contraction: The muscle shortens against resistance.
  • Effortful phase: This is typically the more challenging part of the movement.
  • Strength gains: The positive phase is crucial for building strength and power.

Both the positive and negative phases are important for muscle development, but the positive phase is usually where you exert the most force. Engaging in proper form during this phase can help maximize results and prevent injury.