Isometric strength training is an interesting subject. It has an odd little history behind it and some of its popularity quickly faded when it was shown that it was not the golden goose that it was initially proposed to be. However, just because it didn’t yield the slightly outrageous results that it was initially proclaimed to produce, doesn’t mean it is not an effective training method.
The one interesting aspect of isometric training that is commonly referenced when talked about its lack of utilization is the fact that it is “joint angle specific”. In other words, the strength gains you make when performing an isometric are only transferable to that joint angle and plus-minus a couple of degrees. However, this joint angle specificity issues doesn’t really tell the whole story. You see, isometrics are quite complex (I wrote a book on it Here)
Long story short, the fact that they are joint angle specific can actually be beneficial. You see, sport is typically quick specific and we typically encounter similar joint angles time and time again. Not to mention, in dynamic movements muscle action is typically quasi-isometric, meaning there is little change in muscle fascicle length (depends on the movement). This little change in fascicle length can only occur if the muscle itself is strong enough to maintain this isometric contraction! Thus, being strong at a specific joint angle might actually explain a ton of the discrepancies we see in sport regarding the traditional sense of “maximal strength” and weight training.
sport specific quasi-isometric strength (slo-mo pogo hops)
[embedyt] https://www.youtube.com/watch?v=ajRi3RUuxNQ[/embedyt]
Yes, weight training can increase isometric strength and there is little doubt maximal strength lays the necessary foundation, but isometric strength at specific joint angles might allow the system to function at an even higher level. This is why you see a lot of “traditional” weight room weak dunkers still jump high! They may have found a way to be strong at joint angles that matter most (I played basketball, so naturally I am bias towards dunkers). Now, get that athlete generally strong with the specific ability to create isometric strength joint angles and you might be one step closer to finding a better recipe.
The other side of the coin is the fact that isometrics create neural patterns that are specific to that angle and intent. For this reason, when doing an isometric I truly believe that intent needs to be understood. A motor pattern – muscle action connection needs to be made. Thus using isometrics in conjunction with other dynamic movements may help facilitate this motor learning process.
[embedyt] https://www.youtube.com/watch?v=vgVdzx3lFyg[/embedyt]
Conclusion
Isometrics can be a useful training tool. However, training at critical joint angles needs to be well planned. This is due to the fact isometrics are joint angle specific. Thus, if you can identify these joint angles and integrate them into a holistic training program that involves other exercises outside of isometrics, you may find that they add a nice boost to your training program.
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