Eccentric exercise is the motion of the active muscle while it’s lengthening during a load. It focuses on slowing down the elongation of the muscle process in order to challenge the muscles, which can lead to stronger muscles, faster muscle repair and increasing metabolic rate. Eccentric movement provides a braking mechanism for muscle and tendon groups that are experiencing concentric movement to protect joints from damage as the contraction is released.
Your muscles have tension producing tissue comprising small contractile units referred to as sarcomeres that each contain a thick (myosin) and thin (actin) myofilament that overlap to format a cross-bridge bond. Eccentric actions place a stretch on the sarcomeres to the point where the myofilaments may experience strain, otherwise known as exercise induced delayed onset muscle soreness (DOMS). This will occur with a quick overload or unaccustomed exercises.
Why should we train our muscles with Eccentric exercise?
Eccentric exercises stress the more difficult part of a movement and therefore do more micro-damage to whatever muscle group you’re working. This will improve the size and quality of your tissue. Therefore, this results in a faster rate of muscle and strength growth.
Lasting changes in mobility require not just the stretching of the muscles and connective tissues as the improvements in range of motion (ROM) seen tend to be short lasting. In order to create long lasting effects, we must move our bodies through the new-found ROM and add load through it. Movement creates neuromuscular activations of the stretched muscles, which essentially teaches our bodies how to use that ROM. Greater loads generate greater neuromuscular activation, and is necessary in being able to keep this change in ROM. Eccentric overload exercises create muscular stretch and high amounts of activation, which both contribute to lasting changes in mobility. Evidently, it leads to sarcomerogenisis (the generation of new sarcomers – muscle cells), which lengthens the muscle itself. Therefore, your flexibility will be increased.
Eccentric exercises have been shown to help build incredible strength and decrease risk of injuries. There are a couple of reasons why. First, eccentrics make you use muscle over momentum. And second, they help build your connective tissue.
Data reported by several studies suggests that stretch combined with overloading, as in eccentric contractions, is the most effective stimulus for promoting muscle growth and enhancing the neural drive to muscle. These neurological improvements, along with the changes in the elastic properties of the musculotendinous unit, contribute to the increase in speed, power, strength, and agility.