Isometric training is a strength and muscle building technique in which the joint angle does not change during the muscle contraction. Rather, they are done in a static position instead of through a range of motion. Isometric training has been around for thousands of years, static holds exist in numerous martial arts and forms of yoga. They have gained and lost popularity throughout the years as workout fads come and go and recently, have fallen out of favor to a large degree. They are a lost form of training that has yielded amazing results in the past. Former circus strongman Alexander Zass (1888-1962), better known as “The Mighty Samson” is well known for his successful use of isometric training to accomplish amazing feats of strength. During World War 1, Zass, a soldier, had his strongman career interrupted and was confined to an Austrian prison camp. With no other means to train and fearing he would lose his strength, he began pushing and pulling on the bars of his cell as a means to strengthen his muscles. To his amazement, Zass discovered that this static type of training made him even stronger than what he was doing prior to the war. Zass went on to great success using these isometric techniques. At only 165lbs, Zass was able to catch a 200 pound cannon ball shot from a cannon, break thick chains and bend iron bars. His feats of strength were unparalleled and something the world had never seen; which he completely credited to isometric training he taught himself in prison camp. Zass would go on to publish a course about isometric training. Isometric training is unique in that it allows the muscle to be overloaded absolutely at various joint angles and body positions as well as recruit the maximum amount of muscle at various joint angles. It can be incorporated into a modern muscle-building regimen to overload muscles in ways they have not been previously and take your training and body to the next level.
Isometric training allows you to overload muscles at angles that concentric and eccentric contractions do not allow for as the muscle spends very little time at each particular angle in standard lifts. Power lifters often fractionalize their lifts in order to target particular “sticking points” or isolate particular portions of a lift to strengthen themselves in only one part of the movement. The Soviet weight-lifting researchers also determined that optimal strength gains were achieved with a protocol of 75% concentric, 15% eccentric, and 10% isometric movements. To see how Isometric exertion works, stand in front of a wall and push with one hand against the wall with your arm at a 90 degree angle and notice your various muscular contractions as you slowly increase force on the wall. The body is very efficient and will always use the least amount of muscle possible to conserve energy. The triceps will be the only muscle you feel under light pressure. As you increase force, the deltoid and pectorals will be recruited. As force increases further, obliques, abs, quads, and nearly everything else will come into use until you feel like you are about to explode under the force. This is an easy way to demonstrate the effectiveness of isometrics, however even more important is that the same type of muscle recruitment occurs on a smaller level within each muscle. Since the body is using the minimal amount of muscle fibers possible to do any action, when you are lightly pushing on the wall, only a small fraction of your triceps muscle fibers are being recruited. By the time you feel your abs strain from high force, however, your body has recruited nearly every fiber in the triceps and it is completely overloaded. The triceps was not able to move the wall, so the body recruited more and more muscles to try to do it…This is essentially the principle of muscle overload and isometric training. Basically, isometric training allows for unlimited overload; since the wall will never move, resistance is unlimited. One can then adjust the joint angle to 45 degrees, 120 degrees etc. to target the muscle in slightly different ways and achieve absolute overload in these positions as well.
The main variable in isometric training is being mentally capable of pushing yourself as hard as possible to achieve maximum muscle recruitment. Practicing this will also allow you to develop a much better mind-muscle connection that will translate to other lifting methods as well. While concentric and eccentric movements are still paramount; adding isometric movements into your routine can be very beneficial. Experiment with various positioning and exercises and focus on maximal force for various amounts of times.