Concentric vs. Eccentric Muscle Movement
A lot goes on in your body during a workout, and sometimes, learning more about exactly what is happening can help you work out more effectively so you can get better results. Whether or not you've heard of concentric and eccentric muscle contractions, you can benefit from learning the difference—especially because one of them is often overlooked, but can help you get even better results from your workout.
Muscle movement can be broken down into concentric and eccentric motion. Concentric muscle contraction is what you may typically think of with exercise. It is the standard contraction and lifting motion, when the muscle shortens and its two connection points come close together. This movement is acting against the force of gravity and improves the muscle's ability to pull and lift.
The eccentric contraction is utilizing the same muscle, but acts in the lowering part of the motion. As the muscle lengthens, the two connection points of the muscle get further apart, but the muscle continues to contract. Eccentric contractions normally occur as a braking force in opposition to a concentric contraction to protect joints from damage. During virtually any routine movement, eccentric contractions assist in keeping motions smooth, but can also slow rapid movements such as a punch or kick.
In a basic jab-cross, two punch combination, the extension of the punch (loaded with the glove) would be the eccentric movement. Muscles are elongating and extending. The concentric part of the punch would be the recoil, when you bring the hands back to the 'home' position for protection. The same is true of the kick, with its four parts: chamber, extension, recoil, plant. You can associate the extension with concentric movement and the eccentric part with the recoiling of the kick.
Eccentric muscle movement is often overlooked and left to gravity. However, you’re doing your body a disservice if you’re not focusing on this type of muscle movement. Your muscles can actually generate more force during the eccentric phase of an exercise. By slowing down the negative (eccentric) phase of your exercise, you can help your muscles build greater strength.
This is why, at 9Round, trainers encourage members to focus on form, and perform each movement with careful precision. For instance, loading a squat movement by holding a medicine ball on Round 2 adds resistance. The down part of the squat would be eccentric and the up part of the squat would be concentric. Instead of just dropping into a squat, we suggest slowly lowering yourself, while engaging your muscles.
By training with slower speeds, the muscles can adapt to increase control and stability. This focus on slowing down also helps to concentrate on form and technique, which helps strengthen stability muscles, and decrease risk of injury.