Isometric exercises are executed in static positions.
Related: 20 Heavy Compound Exercises For Brutal Bulk
You may now be asking yourself: "How can I train my muscles if I'm not actually moving anything?" A very valid question. Let's take a look at the following isometric exercises (you've probably heard of some of these) and the muscles that they train.
Common Isometric Exercises
- Plank - Muscle Group Trained: Core (Abdominals and Lower Back)
- Wall Sit - Muscle Group Trained: Quadriceps
- Overhead Hold - Muscle Group Trained: Shoulders
- Glute Bridge - Muscle Groups Trained: Glutes and Hamstrings
- Structural items (for instance, pushing against a wall)
- The body's own structure
- The ground
- Free weights held in a static position
Article author Shomo "Shotime" Das discusses isometric exercises and training.
A Deeper Look at Isometric ExercisesWhen you execute an isometric exercise, you place the stress of the resistance entirely upon the muscle fibers. This eliminates any and all reactive contribution. Isometrics increase muscle motor unit recruitment far more than compound and isolation exercises.
A trainee can only recruit nearly all of the muscle fibers during the execution of a maximal isometric contraction; this response is not seen when performing the eccentric and concentric portions of the repetitions of other types of exercise. At the end of the day, the higher the number of muscle fibers that you are able to recruit, the more extensively you'll be able to train a muscle.
This high muscle fiber recruitment has also been shown to dramatically increase strength (between 14% and 40% strength increase over a ten-week trial period incorporating isometrics in a training regimen, Thibadeau, C. "Theory and Application of Modern Strength and Power Methods" 2004).
Isometric exercises also provide you with a tool to increase the time under tension (TUT) for a specific muscle group that you're trying to target. If you think about the execution of most compound and isolation movements, there are portions of the execution that place less tension (and sometimes even no tension) upon the muscle that you're targeting with the exercise.
Take the bench press. When you execute a bench press, you are looking to train the chest. However, at the top of the movement, when you have completed lockout of the arms, there is no longer significant tension on the muscles of the chest. The time spent at this point of the motion is wasted from a TUT perspective.
Take the dumbbell curl. When you execute a dumbbell curl, you are looking to train the biceps. However, at the bottom of the movement, when you have completed the repetition and your arms are hanging by your torso, there is no longer significant tension on the muscles of the biceps. The time spent at this point of the motion is, again, wasted from a TUT perspective.
The list goes on and on.
With compound and isolation movements, if it takes you 30 seconds to complete a set. You may only be placing tension upon your target muscle for 5-10 seconds per set.
With isometric movements, you can really isolate a specific muscle and prolong this time under tension, and prolonging TUT certainly plays a role in increasing hypertrophy, improving your "pump", and progressing your muscle building motives.
Starting With Isometrics for Strength ImprovementsThis next, and last, point may be surprising to you. But placing isometric exercises at the beginning of your workout routines can cause your strength to increase as you continue along with your workout.
Yes, you read that right. We have been conditioned by conventional wisdom to assume that we should be losing strength and energy as we continue to train longer and longer, but isometrics defy this theory.
Not only do isometric exercises cause muscle breakdown themselves, but they also cause an immediate increase the the dynamic work that follows them. So, what does this mean? Well, this means that you can perform an isometric exercise and experience a strength increase with the next movement that you execute.
This may be something that you need to see before you believe. I get it; it sounds ludicrous. But I have experienced this reality first hand, and you can too.
To summarize, isometric exercises should be included in your training regimen because:
- They increase muscle motor unit recruitment far more than any other exercise type
- They increase TUT, thus increasing hypertrophy
- They can cause a strength increase for the exercises that follow them in your routine