Our muscles have 3 main contraction types and they are used in common everyday movements. They are the contentric, isometric and eccentric phases. Here's a quick rundown:
Concentric - muscle fibers are shortening in length while under tension. In the example of a biceps curl, this would be in the lifting phase. The mucle length shortens to bring the weight up to the top of the movement
Isometric - muscle fibers are maintain the same length while under tension. This can occur anytime the weight is held motionless without any upward or downward movement.
Eccentric - Muscle fibers are lengthening while under tension. This is often referred to as the "negative" of the movement, when the weight is being lowered to the ground
Video explanation of the three phases of movement:
As the video mentions, the eccentric phase is capabale of generating substantially greater forces than the concentric and isometric phases. There a many factors that make the eccentric contraction stronger including varying neural strategies, specific fiber type activation as well as structures such as a spiral protien called titin.
Eccentric actions are a part of our daily lives, for example, walking down the stairs or putting down a bag of groceries. They are also vital to athletic performance, for instance, changing direction, or landing from a vertical jump. As such, there are many benefits to employing eccentric loading to increase sports performance as well as everyday function and longevity.
Stay tuned as we dive into the many benefits of eccentric training, how to employ it as well as precautions and methods to perform it safely.