Utilising Isometrics
Overview
Isometric is a term given to a muscle contraction that is static in nature, it can be either in holding a joint in place for example the elbow flexors when holding a cup of tea, or like trying to move against a very heavy resistance such as at the knee, hip and ankle extensors when trying to push a car with the handbrake on.
They can also occur for very short periods in dynamic movements such as during plyometrics (movements with a ground contact time of less than 0.25 seconds) the amortisation phase is the period when a muscle transitions from eccentric (lengthening) to concentric (shortening). This also occurs during the transition from up to down in squats, hinges, presses etc.
Regarding training they have been popular for decades, especially for the trunk with planks and the like still being many people's go to trunk choice. Strangely though this popularity has not been as wide spread to other movements or areas of the body.
Types
Overcoming (pushing) These involve pushing against an immovable object much like our car example. Pins also work great in the gym or placing more weight on than you can lift but still trying to overcome it. This simulates the concentric (shortening action) and can be done at specific positions to improve max force outputs or the rate at which force can be produced (Rate of force development). Generally these will be done for <15 seconds for multiple reps and work up to maximal effort.
Yielding (holding) Here the job is to hold a position without losing the starting joint angle, the resistance is making the muscle want to move eccentrically (lengthen) but you must hold the position. Think of Maximus saying ‘Hold the line! With me!’ In Gladiator. Yep you’ve got it.
These happen to be the more fatiguing of the two. They are most often prescribed between 3-45 seconds but rarely at such a high intensity like that of overcoming.
Badger protocols First seen on Complementary Training Badger protocols combine dynamic reps with yielding isometrics, in theory overcoming isometrics could also be a great option.
It involves a set number of reps performed first as seconds of an isometric typically in the most mechanically and metabolically challenging part of a movement such as the bottom of a squat. Then the reps are completed followed by another hold.
For example: If reps are 10.
10 second hold bottom of squat
10 Squats
10 second hold bottom of squat
Intensity has to be far lesser than that of a 10 reps maximum (75% roughly) due to the increased time under tension, but this gap reduces as the reps do.
Top and bottom Badger can also be executed with top holding only at the start, and bottom at the end.
Measurement
In order to prescribe and monitor isometric training you need to have accurate and reliable measurements. Unfortunately this can be quite expensive for the recreational athlete, requiring either force plates or gStrength equipment and software to provide precise measurements for rate of force development, and max force outputs.
Although such technology provides the gold standard for measurement three variables do exist that can be measured using a timer, coach and/or camera. They are:
Time - how long you held the position for, or how long you have available to produce a max effort.
Load - How much load you held or could not move.
Position - was the joint angle and overall position maintained.
Application
These variables can struggle to really capture an accurate account for overcoming isometrics, although one method I have explored is using a load that you can only just not move, and if you do move it, even slightly after previously not being able to then your strength in that position has increased. An example being a single leg extension at 60 degrees and being able to overcome a set load - to briefly mention this carries a higher risk due to maximal loads being moved, so once a slight concentric movement occurs the weight should be lowered back to the stable resting position and the load increased to once again become an overcoming isometric.
For Yielding and Badger protocols the three variables above can provide great prescriptions. What’s then missing is the effort. RPE (Rate of perceived exertion 1-10 scale, 10= max) or % of either one rep (1RM) or relative max can be used to great effect. With RPE also being effective for overcoming isometrics.
As with most training longer durations are prescribed with lower intensities and vice versa.
For example Badger Protocol for 10 sec - 10 reps - 10 sec would be prescribed at 40-50% of 1RM. A 10RM would be roughly 75% of max, but with the long yielding isometrics either side this would be very unrealistic.
Isometrics are a form of strength training, therefore if they are utilised in a program it would be at the expense of other forms of strength training. It is not something you would add on top of everything else like an overfilled pizza. It would be in exchange for another part. Famous Strength coach Big Dan John has said on numerous occasions ‘more is just more’, something similar has also been said by author of Four Thousand Weeks Oliver Burkeman. Which brings us nicely to our final part of the discussion.
Why not just do Dynamic exercises?
A fair question. In no way is isometric training supremely better than dynamic exercises, the opposite is also untrue. They are both tools to drive a specific adaptation in a certain context.
Here are some contexts where isometric training could be favoured;
If recovering from an injury, tissues respond to load so to recover and rebuild load needs to be applied - isometrics provide a controlled contraction that can be safely ramped up in effort and stopped if the force is too great in targeted positions that need to be strengthened.
They are simple to do, requiring far less technical development than some other exercises yet still allow for very high force outputs whilst also being performed at specific angles in relation to sports skills or mechanically disadvantages positions where dynamic exercises may struggle to provide overload. For example you can set up an overcoming isometric on one leg using a barbell and pins in the stance phase of running (see image below). From here you can work on rate of force development, pushing into the bar as hard and fast as possible or work max force pushing as hard as possible for a set duration. Such an exercise is very hard to recreate with dynamic exercises if force development is the emphasis due to large levels of instability on one leg.
Delayed onset muscle soreness (DOMs) is a sought after sensation for some, but a major problem for others. The bottom line is that it reduces performance when it is prevalent, so if you want to perform at your best but are sore this is going to be a difficult task. Eccentric contraction (muscle lengthening under tension) is the primary culprit for DOMs due to high mechanical tension on muscle fibres especially in fully lengthened positions. Therefore Isometric and concentric (muscle shortening) contractions are favourable to develop or maintain strength close to a period where peak physical performance is required. Not to disregard the benefit of eccentric training, due to the mechanical and metabolic disruption it causes it can be a great stimulus to develop performance providing enough recovery is provided.
A common criticism of isometrics is that they only strengthen muscles at specific positions with limited transfer to other joint angles and do not yield the same gains in muscle hypertrophy as dynamic contractions, this notion has been challenged in recent research when training a joint isometrically at longer muscle lengths (Alegre et al., 2014; Kubo et al., 2006; Noorkoiv et al., 2015).
Finally, tendon stiffness has also been shown to increase following isometric training protocols associated with greater rate of force development and economy in endurance runners.
Of course there are some limitations when comparing to dynamic exercises, including more difficulty with prescription compared to traditional dynamic exercise using % of 1RM, especially for pushing isometrics without the use of force plates or the like. Balance and positional control may not be developed to the same degree as with dynamic exercise and the duration of progression is not clear with most research lasting only 6 weeks. Anecdotally large parts of a Gymnastics rings specialists training is isometric and they develop phenomenal upper body strength, although the transfer is to isometric strength skills such as planche and cross and their training is combined with dynamic and isometric exercise.
Finally buy-in for athletes needs to be attained, some may find it awkward or difficult to set up in the gym, shaking and pulling funny faces as you try to drive a barbell up into the pins does look a little unconventional. Let's face it, so do most things we see in the gym - a little exercise for you… in your mind eye remove the equipment from sight and watch what people do in the gym, we're basically just doing a structured dance routine.
Try them out
I do not believe isometrics should completely replace traditional dynamic exercises so you can try replacing some sets instead - for example replace 5 sets of squats with 3 sets plus 2 isometric sets. Use the adaptation to decide the rep range and intensity.
Danny Lum also utilises them as complex sets with a maximal overcoming isometric followed by a plyometric or ballistic after a full recovery of 2-5 minutes for multiple sets. A great option to peak athletic performance.
Yielding options typically are performed for longer durations with less intensity due to larger mechanical and metabolic stress, you should always be able to safely lower the load if performing close to maximal yielding isometrics.
*RPE refers to starting effort, which will increase as time progresses.
*Max strength followed by Rate of force development
Example day - General Strength, Push.
Emphasising general strength in pushing patterns such as squatting, pressing and split stance squatting and muscular hypertrophy of the quadriceps, elbow extensors, shoulder flexors and calves.
a.Back squat 3 x 8 reps @70%
a2) Overcoming isometric squat at 110 degrees of knee flexion 2 x 3 reps of 15 seconds @5 RPE
b. Z press 2 x 10 reps @65%
b2) Hold bar at eye line (set above pins) for 2 x 30 seconds @50% after each set
c. DB Split squat Badger protocol 2 x 10 sec - 10 reps - 10 sec each side @40%
d. Dip 2 x 10
d2) Single leg calf raise 2 x 15 es.
e. Bear crawl 3 x 1:00 on / 1:00 off
