Concentric and Eccentric Muscle Contraction
Most people reading the title are probably quoting Servilius Casca’s most famous line, “It’s all Greek to me.” But have no fear, the confusion is about to disappear!
Eccentric and concentric are terms that refer to two different types of muscle contraction. Eccentric contractions are when the muscle resists against a force that is lengthening the muscle (ex. lowering a bench press to the chest). Concentric refers to moving against resistance when the muscle is shortening (ex. pressing the bar off the chest in a bench press). It is always important to control the eccentric portion of every lift and to explode through the concentric portion of the lift. The eccentric portion of a lift should always be slightly slower than the concentric to prevent injury and to also work the muscle more by keep it under tension for a longer time period.
Negative reps refer to the over load of resistance to the point where concentric contractions usually are not possible, but exaggerated eccentric contractions can still be present. This results in large amounts of muscle damage and should be done with an experienced spotter and by experienced weight lifters. The high amounts of muscle damage can possibly lead to injury or over training in a novice lifter, but the results yielded can be great for adding size and strength. For athletes it will also help in the body’s ability to decelerate force, which makes them move more efficiently and also drastically reduces the chance of injury. It is also a great plateau buster.
Become aware of both portions of the lift, make sure your eccentric contractions are a bit slower and are more controlled. Understand you must forcefully contract the muscle and explode through the concentric portion of your lifts. Remember, this tactic can be applied to almost any lift. Have fun with it!