Muscle Contraction Vs Concentric Contraction

Concentric contraction is when the muscle is activated to lift a load less than the amount of force the muscle can take. This causes the muscle fibers to contract. Concentric is the up phase of the exercise. This is being done with gravity, so the movement is much easier. Going back to the bicep curl, this is the up phase bringing the weight back to you. (Johnson, 1996)

An eccentric contraction can use both active and passive movements. This is why eccentric movements can create a bigger strength gain than concentric contractions. The passive movement resists the lengthening of the muscle fiber in the eccentric contraction, but not in the concentric contraction. (Herogz,2014) Active movements affect both types of contractions. In the eccentric phase the

This makes an eccentric contraction more efficient than a concentric action. Due to the amount of energy needed for each contraction, the eccentric contraction has more endurance and will be able to perform more repetitions and create bigger strength gains. (Kelly, et. al., 2015)

Studies have shown that eccentric training does create more strength gains than a concentric contraction. During an eccentric contraction the muscle must adapt and change because of the movement. There are six different adaptations that occur during this contraction. The first deals with the muscle architecture. The architecture can be affected by the fascicle length and pennation angle. The fascicle length is shown to increase after eccentric training due to the stretch that occurs when training. When that muscle gets lengthened it tends to cause more positive adaptations in muscle strength. The pennation angle is shown to increase due to concentric training. Due to this focusing on fascicle length is more beneficial than pennation angle. (Kay et. al., 2016) The second adaptation is muscle fiber type. Even though you may think muscle fiber type will cause strength gains, it actually does very little.