What if I told you, you could get bigger, stronger, with healthier muscles and tendons by performing exercises where you don’t move… at all. Dynamic exercises such as your traditional exercises are not the only way to make gains.
Isometric exercise is great for improving isometric strength and for building muscle mass, especially when performed at long muscle lengths. Whether isometric strength transfers well to dynamic strength is yet to be fully determined within the literature.
Before diving into the science of how isometric exercise can help you become an unstoppable beast, we must first define what an isometric exercise is.
What Is An Isometric Exercise?
Isometric exercise is an exercise where muscle tension is created without a change in muscle length. Essentially, you are exerting force without any movement. You can even try it out for yourself! Try to push the wall over in your home or office. Because your wall won’t budge, you are not moving creating an isometric exercise.
Isometric vs. Isotonic
You may not have come across the term isotonic before. Or even isometric. But to quickly clarify in case you do come across these terms outside of this article. Isotonic exercise involves a muscular contraction with a change in muscle length against a constant load.
This is just a fancy way of labeling any basic strength training exercise. For example, a back squat with 100 lbs on the bar is an isotonic exercise as you are contracting against a constant load of 100 lbs.
But the load doesn’t have to be external. Even bodyweight counts. For example, a push-up is an isotonic exercise as the constant load is your bodyweight. If instead of performing a push-up, you held the bottom position of the push-up, there would be no change in muscle length and therefore would be an isometric exercise instead of an isotonic exercise.
Isometrics For Strength
Now we have a general understanding of isometric exercise, it’s time to dive deep into the details that will make you strong as a bull. Here’s what you need to know in bullet point form.
It is relatively well known that isometric strength is specific to the joint angle being trained. For example, if you trained isometrics in a quarter squat position, you wouldn’t see much of this strength transfer to the parallel position. This has been demonstrated in a study that had subjects train isometrics at a 65° knee angle .
The greatest increase in strength was found at 65° but also surrounding joint angles of 85° and 50°. So, if you wanted to improve isometric strength in deep knee flexion, then you’ll need to train in that position or closer to it.
However, it seems that isometrics at long muscle lengths transfer to strength at all joint angles to some extent whereas shorter muscle lengths only correspond to the angles closest to it [2,3].
But does this isometric strength transfer to dynamic strength (i.e. movement)? We don’t have much research in this space but it seems that isometric exercise may transfer to dynamic exercise.
Two studies found that isometrics at long muscle lengths improved isokinetic torque at slow speeds whereas short muscle length isometrics did not [4,5]. The lone study to use squat and jump performance found both short and long muscle length isometrics to improve 1RM and jump height .
One mechanism for isometrics potentially transferring to dynamic strength performance is the increase in tendon stiffness. A stiffer tendon can transfer more force from muscle to bone and therefore, you're able to lift more weight .
Contraction intensities greater than 70% effort are needed to increase tendon stiffness and it seems that explosive isometric efforts (pushing or pulling as hard and fast as possible) and using long muscle lengths will have the greatest effect on tendon stiffness .
If the goal is to improve the ability to produce force in the shortest time frame possible (i.e. rate of force development or RFD for short), then you should also perform explosive isometrics as this has greater benefits for RFD than other methods .
Isometrics For Hypertrophy
There are a couple of ways you can use isometrics to maximize hypertrophy. One is to use them as main exercises within your training session. These isometrics should be performed at long muscle lengths as this is what creates greater metabolic stress (a key mechanism for building muscle) and muscle damage compared to short muscle length isometrics .
The intensity of these isometric contractions doesn’t seem to matter when it comes to muscle growth. Rather, progress your isometrics by increasing the duration of each set and increasing the total volume (number of sets and reps) .
For example, 4 x 30 seconds at maximum effort resulted in greater muscle growth than 4 x (10 x 3 seconds) at maximum effort even though total volume was equated .
The other method is using isometric exercises during the rest periods of your main exercises. One study had subjects perform 30 seconds of a maximal isometric contraction during the rest period for the main muscle group being worked in the main exercise .
Muscle thickness of the quadriceps increased after the training intervention making this a plausible method to use isometrics as a way to enhance muscle growth.
You may be surprised to know there are different types of isometric exercises. Some of these are better than others when it comes to developing strength and hypertrophy. These are overcoming, yielding, and eccentric quasi-isometric exercises.
Overcoming Isometrics For Strength And Hypertrophy
Overcoming isometrics are applying as much force as possible against an immovable object. The example of pushing your wall over is a prime example of this. Within the gym, placing the barbell under the supports of the power rack and pulling against it as hard as possible is an overcoming isometric exercise example.
These are most applicable to developing strength and RFD and to some extent, hypertrophy when long enough contraction durations are used.
Yielding Isometrics For Strength And Hypertrophy
Yielding isometrics differ from overcoming in that instead of exerting as much force as possible against something immovable, you are holding a position for a period of time. For example, you could hold the bottom of a Romanian deadlift for 30 seconds with a light load.
Interestingly, when comparing holding a joint angle with a load versus maintaining a constant push with the same force, subjects were able to maintain the position for twice as long when pushing versus holding [9,10].
This is likely due to more muscles being involved during the holding task where contractions of the muscles around the joints are greater than when pushing .
Therefore, yielding isometrics may be great for improving position-specific strength. For example, Olympic Weightlifters will often use pauses mid-way through their pulls.
This increases time under tension and creates positional strength by increasing the activity of the surrounding muscles of the hips and back.
Eccentric Quasi-Isometrics For Strength And Hypertrophy
Yea… the name sounds too scientific to lead to any gains. Eccentric quasi-isometrics are defined as “holding a position until isometric failure and maximally resisting the subsequent eccentric phase.” . An easy visual would be starting a glute-ham raise from the top position. Lower yourself slightly forward and hold that position as long as you can.
As you start to fall, don't just drop. Keep resisting as long as possible to the bottom. That is an eccentric quasi-isometric. Here is a video example of a single-leg leg extension:
Eccentric quasi-isometrics may be an efficient way to increase the total load, volume and may provide a strong modality for tendon and muscle rehabilitation . Essentially, you’re able to use higher intensities for longer set durations or for more total work resulting in greater mechanical tension and metabolic stress.
You may even preferentially recruit type II muscle fibers due to the isometric contraction reducing the oxygen supply and clearance of waste products . Therefore, eccentric quasi-isometrics may be a viable exercise modality to improve muscle size.
Now we’ve covered all of the different forms of isometric contractions, here are the best isometrics for strength and hypertrophy development that you can use at home or within the gym.
Best Isometrics For Strength And Hypertrophy
Split Squat Isometric Pull
If you want to develop unreal single-leg strength and power, use the split squat isometric pull. Set the pins so the bar when lifted still fits between your legs. Straddle the barbell and lift the barbell against the pins.
Once ready, pull as hard as you can against the pins like you’re trying to flip the power rack. Use straps so your grip isn’t the limiting factor. Use approximately 6 seconds of maximal pulling for strength and 20+ seconds for hypertrophy.
Isometric Mid-Thigh Pull
This is an exercise that is used to produce the most force out of any isometric exercise. The isometric mid-thigh pull is often used as an athletic performance test to measure peak force. However, you can also use it as an isometric exercise to develop crazy pulling strength.
Simply set the pins high enough so the barbell when pulled is at mid-thigh height. Again, use straps and pull as hard and as fast as possible. Use approximately 6-10 seconds of maximal pulling for developing strength and RFD.
Overhead Press Against Pins
This exercise is a full-body killer. You’ll feel it through your whole body and especially your shoulders. This can be a great exercise to push through sticking points. You can play around with where you place the pins.
Just above the head is a good place to start and you can move them up and down from there to work the areas where you fail the lift. You can use a range of isometric durations with shorter durations for strength and longer durations for hypertrophy.
Isometric Bench Press Against Pins
Just like the overhead press, you can do the same with the bench press. Setting the pins midway through the bench press is a good place to start and you can move them lower or higher depending on your sticking point.
Having the pins lower can train the isometric contraction at longer muscle lengths and potentially lead to greater muscle growth with longer contraction times.
Chest Supported Isometric Row
While this is an isometric at short muscle length, it makes a great exercise for those in wrestling and collision sports that require manipulating other humans. Holding for long durations can develop strength endurance of the back and arms while shorter maximal contractions will be a strength builder.
I like the use of plates as it’s easier to set up and doesn’t ruin equipment. Pulling a barbell into a bench may not be great for the bar.
Isometric Romanian Deadlift
I couldn’t find one decent video for this exercise so I’m going to have to make one. But in the meantime, the exercise is relatively self-explanatory. Simply perform a Romanian deadlift to the bottom position and hold.
FIGHT MAINSTREAM FITNESS & MAKE ASTRONOMICAL GAINS
This is not an overcoming isometric like the above exercise examples. This is a yielding isometric. It will improve your overall flexibility and strengthen all of the muscles around your hips and back and strength the bottom position of the exercise.
Hold this position for 20-30 seconds with a moderate load.
Long Duration Isometric Split Squat
This is another yielding isometric favorite that I often use to help with knee pain. Simply lower yourself into the bottom of a split squat and hold for a long, long time. I’m talking 60 seconds minimum and up to 5 minutes.
This exercise provides an analgesic or numbing effect on the patella tendon making it a perfect warm-up exercise before a lower-body session .
Isometric Push-Up Bottom Position
If you want an isometric exercise to aid your shoulder health and build strength in vulnerable positions, then you need to use the bottom position push-up isometric. These also count as a long muscle length isometric so can be a great muscle builder for your pecs. Try finishing your chest workout with these and feel yourself shake.
Eccentric Quasi-Isometric Glute-Ham Raise
This is essentially like a Nordic drop where you start to fall forward, but once you start to feel the pressure on the hamstrings, stop and hold. You’ll hold this position as long as you can and as you fatigue, you’ll reach the horizontal position.
This is better to do in the glute-ham raise as you have a pad and foot support to create pressure so you can hold these positions longer than a traditional Nordic.
Your goal is to aim for anywhere from 5-90 seconds. The longer the better.
Eccentric Quasi-Isometric Leg Press
To start the eccentric quasi-isometric leg press, lower the weight slightly and hold the position for as long as possible. As you fatigue, you’ll lower to the bottom position. Make sure to set the safety at the bottom so you don’t crush yourself. Your goal is to aim for anywhere from 5-90 seconds. The longer the better.
Eccentric Quasi-Isometric Pull-Up
This is one for the upper body and will smoke your lats. Start with your head just below the bar and hold the position as long as possible. As you fatigue, you’ll slowly lower until your arms are fully straight. Your goal is to aim for anywhere from 5-90 seconds. The longer the better.
Isometric Training Benefits
Isometrics provides many strength, hypertrophy, and rehabilitation benefits. But they also provide a rather underutilized benefit. And that is the idea of post-activation potentiation. Because of the hefty neurological stimulus of overcoming isometrics, we can use them to potentiate the next exercise.
Meaning using isometrics at the start of your workout or as part of a complex (a superset of a high force exercise with power or velocity-based exercise) can enhance the outputs of the subsequent exercise.
An example might be using an isometric mid-thigh pull before a session of power cleans or hang cleans. Or overcoming isometric bench press against the pins before bench pressing. These must be performed in low volumes so you don’t carry over fatigue.
For example, 2-3 sets of 6 seconds of maximal contractions. The same can be used as a complex. For example, split squat isometric pulls superset with split squat jumps.
Isometric Exercises For Beginners
Some of these exercises are out of the scope for a beginner. They require the ability to produce a lot of force to be useful. Beginners generally aren’t capable of “unlocking” their force capabilities due to inhibitory mechanisms within the muscle. The desensitization of this inhibitory mechanism comes with time under the bar and lots of heavy lifting.
However, the use of yielding isometrics like the long duration split squat, isometric Romanian deadlift, and isometric push-up in the bottom position is great for beginners as they teach the proper positioning and strengthen those positions without much load.
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