Did you know that there are 3 different types of muscle contractions?
It's important to get to know the different types so that you can maximize your strength gains and train more effectively. In this post, i'm giving you a quick breakdown of each to help you better understand.
First off, a little anatomy lesson...
It is important to understand the different parts of a muscle to get a better idea of how a contraction occurs. The origin of a muscle is where it attaches to a bone closest to your trunk. In other words, it is where the muscle originates from. The origin generally stays stationary and does not move as contraction occurs.
The insertion point of a muscle is where the other end attaches. During contractions it is the insertion point that pulls on the bone and causes movement at a joint to occur.
Each muscle itself is made up of many tiny fibers that slide past one another to either shorten or lengthen the muscle. I won't bore you with the nitty gritty, but put simply, the sliding of these fibers is what produces a muscle contraction and is the basis for all movement.
So here are the 3 ways that a muscle can contract, or "activate"...
In this type of contraction no change in muscle length occurs. The origin and insertion do not move closer or farther away from one other. This is the most basic type of muscle contraction and the easiest to perform.
Try it out: With your knee extended, imagine pushing the back of the knee down to the floor and drawing the knee cap upwards towards your hip. See how that quad muscle contracts without the knee actually bending or straightening? This is an isometric quad contraction.
In rehab, we sometimes start with these contractions when you are trying to re-learn a movement, such as after a surgery. However, isometrics have a place in more advanced training as well. You can isometrically hold a weight in various positions to help build up muscle endurance and ability to resist fatigue.
Here are a few more examples of ways you can incorporate this type of exercise:
Isometric bicep curl- holding a weight, hold your elbow bent at 90 deg for 20 seconds
Isometric bridges- with knees bend, lift your pelvis in the air. Hold this position for a period of time (20 seconds). This is an isometric glut and hamstring exercise.
In this type of contraction the muscle fibers are shortening, so the insertion point of the muscle moves closer to the origin. This type of contraction produces power in the muscle. It is the next most challenging type of contraction and the most common type of weight training exercise.
Incorporating concentric activities into your workouts will help you to improve your overall muscle strength and power. During concentric contractions it is important to pay attention to your form and technique to make sure the muscle is working most efficiently.
Here are a few examples of how you would turn the above isometric exercises into concentric ones:
Bicep curl- Holding a weight, lift and lower your forearm for 2 sets of 10 reps. You can add weight, sets or reps once the current level you are at becomes too easy.
Bridges- While lying on your back repeat lifting and lowering your pelvis for 2 sets of 10 reps. You can also add weight to this if necessary.
In this type of contraction the muscle fibers are elongating, so the insertion point moves farther away from the origin. It is much more difficult to perform an eccentric contraction because not only does it focus on strength, but it requires a high level of stability, control and coordination. If you are an athlete or dancer- you better get good at these!!
You should always make it a point to include eccentric exercises into your regular routine. Because this type of contraction is the most difficult to perform, it also builds the most amount of strength in the muscle. Plus, as I've mentioned, it works on coordination and control. Both are key elements to enhancing your training and preventing future injuries. You need to be able to first complete a solid isometric and concentric activation before you start incorporating eccentrics, and most importantly you must always maintain good form.
Sticking with our bicep curl example: Holding a weight with your elbow fully bent, slowly start lowering the forearm maintaining good muscle control throughout the entire range. The slower you move, the more difficult the work.
So why does all this matter??
Now that you know what each type of muscle contraction is, it is important to think of it from a functional perspective. Our bodies are constantly producing each types of these contractions on a daily basis without you even realizing it. They work in sequence with each other to produce all of our movements, so while one muscle is shortening concentrically another is eccentrically lengthening. An example may be easier to understand so lets look at the simple, yet functional, movement of sitting down in a chair (a.k.a. squat):
When you are lowering your buttocks towards the chair your hamstrings are shortening and quads are lengthening. In other words, your hamstrings are concentrically contracting and your quads are eccentrically contracting. If these 2 muscles did not work together this way, we would not be able to coordinate and control our movement enough to sit down in a chair without falling.
My point is that when you are thinking about exercising, it is not just about building up muscle tone and strength- it is improving your bodies capacity to complete functional movements on a daily basis. Of course, sitting down in a chair is an easy example but keep in mind there is an orchestra of movements that are occurring with every task you do, from a lift of the finger to moving heavy furniture. It is quite fascinating to think about what occurs within our bodies without us even being aware!!
I hope that this has given you something to think about next time you are exercising and some new things to try! Comment below with questions or your favorite ways to incorporate different types of muscle contractions into your own training!