[No. 265] Understanding Muscle Movement: Training Through 3 Types of Contraction 🏋️♂️🧠
There are broadly three types of muscle contraction.
・Concentric contraction
・Isometric contraction
・Eccentric contraction
Strictly speaking, there is also a classification called "Isotonic contraction," but
in general training understanding, it is often explained using these three.
In actual strength training, everyone performs these movements naturally.
However, they are not often consciously thought of as terms.
I happened to have the opportunity to learn about these contraction types in physical therapy school.
As I continue my training, I am feeling the importance of this concept once again.
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Concentric Contraction: Movement where the muscle shortens 🏋️♂️📈
Concentric contraction is a contraction where
the muscle exerts force while shortening.
It is commonly seen in so-called "lifting movements."
With the elbow as a fulcrum, lift while focusing on the biceps brachii.
The muscle exerts force while shortening—concentric contraction.
For example,
・The movement of lifting a dumbbell in a dumbbell curl (biceps brachii)
・The movement of pushing up a barbell in a bench press (pectoralis major/triceps brachii)
In these situations, the muscle is exerting force while contracting.
In training,
focusing on the muscle at the moment of contractionis important.
Isometric Contraction: Exerting force without changing length 🧱⏳
Isometric contraction is a contraction where
the muscle exerts force without changing its length.
The muscle is working while there is no joint movement.
Stabilize the core while keeping the body in a straight line.
The muscle exerts force without changing its length—isometric contraction.
For example,
・Core training to hold a plank position (rectus abdominis, transversus abdominis)
・Holding a squat in a mid-position (quadriceps, gluteus maximus)
The movement is stopped, but
the muscles are under significant load.
In training, this is utilized as
the power to maintain or hold a posture.
Eccentric Contraction: Muscles generating force while lengthening 📉💪
Eccentric contraction is a contraction where
the muscle generates force while being stretched.
It is commonly seen in so-called "lowering movements."
: During the phase of slowly lowering the body, the quadriceps and glutes work.
Muscles generating force while lengthening—this is eccentric contraction.
For example,
・The movement of slowly lowering a dumbbell curl (biceps brachii)
・The movement of lowering the body in a squat (quadriceps, gluteal group)
In this phase, the muscles are under load while being stretched.
Generally,
eccentric contraction is considered to easily provide strong muscle stimulation.
Therefore,
many training routines emphasize the movement of lowering slowly.
Understanding contraction types 🧠🏋️♂️
For concentric contraction,
focus on shortening the muscle.
For isometric contraction,
focus on holding the posture.
For eccentric contraction,
focus on controlling and receiving the load.
Just by having these perspectives,
the quality of your training will change significantly.
This applies to more than just strength training.
Even in daily movements,
muscles are constantly repeating these three types of contractions.
Understanding them correctly
not only increases stimulation to the muscles but also leads to injury prevention.
The concept of training the whole body 🌍💪
Barbells, dumbbells, machines.
The equipment used varies.
Deltoids
Pectoralis major
Latissimus dorsi
Quadriceps
Hamstrings
Triceps surae
Tibialis anterior
The muscles being trained are also different.
However,
the contraction patterns of muscles are all common.
Previously, a bodybuilder I respect said something like this.
"It is important to train the whole body."
If one part is weak,
the burden will concentrate there.
That is why,
you should train your whole body without bias.
Understand the contraction patterns,
and use your entire body in a balanced way.
That, too,
might be the essence of training.
⚠️ Caution
💪 This article is based on the author's experience and personal thoughts.
🏋️♂️ There are individual differences in the effects and methods of training.
⚠️ Please perform exercises safely according to your physical condition and environment.
✅ Please take responsibility for your own judgment and actions.
Underlying × Cultivation
Fields, bodies, and investments—a way of life that keeps on tilling.
Renji Enko