My favourite way of exercising is using your own muscular tension. It goes under a few different names, but I prefer the term “focused muscular tension exercises”, because it encompasses all different modes of training. How you use the tension is different between systems. There are exercise systems where one visualizes to lift a heavy weight or to move around in mud or any other viscous material that provides tension. Here the internal tension is generated by the agonist (the muscle responsible for your movement, e.g. the contracted biceps in normal biceps curls) working against the antagonist muscle (the relaxed triceps in normal biceps curls). So in practice, if you are doing a similar exercise like a classic biceps curl in this way of practice, you either imagine lifting a heavy weight or you directly focus on generating tension in your biceps and triceps simultaneously – thus providing a stimulus for your muscles by letting them work against each other. In other systems, tension is generated by dynamically working limb against limb. Take the classic biceps curl again. Instead of a weight, your other arm provides the necessary resistance. Charles Atlas was a proponent of this system. A similar method is to work against immovable objects where you focus on generating maximum tension. These exercises are called Isometrics. “Isometrics” meaning no length change in your muscle is occurring, i.e. no actual movement is happening. Another interesting method is to tense only the muscle involved at the point where the muscle is maximally shortened. Take again the biceps curl, this time only tense the biceps at the end of upward movement (like you would flex your biceps). This method can be done statically or dynamically. The later one is often done with a light dumbbell to intensify the feeling and the tension, thus creating the correct stimulus.
The idea to train with muscular tension is of course nothing new. In some Karate styles, there is the Sanchin form and in Hung gar kung fu there is the Iron wire form. It seems that – at least from the point of view of a relative new chronologically traceable history – most systems originate from a Strong man (and his related contemporaries) named Ludwig Durlacher, who gave himself the stage name “Professor Attila”.
Many strongmen and physical culturists can be traced back to this man. His System was based on training with “5-pound-dumbells”. Thanks to the work of David Bolton who researched this system and its history, the information is now out in the open. He argues that the 5-dumbell system has not much to do with simply lifting 5 pound dumbbells. Instead, the dumbbell is only a tool to provide the right feeling and an extra stimulus for focused muscular tension. A good source to verify this statement, which he also quotes, is the work of one of Prof. Attila`s student Al Treloar. Although the weight can be increased after a while, it is however important not to exceed the point where the weight of the dumbbell become the main focus. The exercise system is still about Focused muscular tension.
Let me now tell you, how I use all the different systems and for what specific goals. As all systems focus on generating tension with your own muscles, all system will more or less improve voluntary control and action of your muscles. Still, as the 5-pound systems focuses on learning how to relax and tense only the agonistic muscles it is the best system for this cause, followed by Isometrics. The constant tension and relaxation in the 5-pound dumbbell system will cause occlusion effects in your muscles and because you work in a rather high rep range you can expect the same effects as with regular strength endurance work. You can expect aerobic effects, fat burning and as well as new research suggests hypertrophy and growth in your type I fibres.
If you want to test your maximal strength in the proper meaning of the word (e.g. Fmax iso), you would have to test it against an immovable object (as is the case in a special developed device) as only then can you activate as much fibres as possible.
Thus, isometric training is best suited for developing your maximal strength. However, this is not generally true, as there is a possibility to use a special protocol for Hypertrophy as well. The goal for hypertrophy training is to activate as many fibre as possible until they are fatigued. The Timed Static Contraction (TSC) protocol of Drew Baye exploits the so called “Henneman´s size principle”, which states, that under load first type I fibres are activated and starting with Fmax > 25% more and more type II fibres are activated. Thus, in the protocol you contract against an immovable object with about 50% of your estimated Fmax for 30s, 75% for another 30s and for another 30s give as much as you can. This has a similar effect as normal hypertrophy training.
To me, the exercises where you are working with the agonist vs. antagonist principle are most suited for improving mobility, flexibility and general limberness. I try to incorporate them throughout the day or when I need an extra session addressing those things. In the context of muscular tension exercises, it does sound cliché to point to animals “stretching”. I deliberately put stretching in quotes, because they are not really stretching in the conventional sense, animals pandiculate. They “stretch” their limbs and spines while simultaneously contracting their muscles. In PNF or isometric stretching a similar approach is used to achieve improved range of motion. You contract the muscle that you want to stretch for a few seconds, then release the tension and relax into the stretch. The theory behind PNF or isometric stretching is that the Golgi-tendon-organ detects the tension and in turn an autogenic relaxation reflex occurs, which allows you to go deeper. The same principle can be used with the agonist vs. antagonist exercises. Therefore I discard exercises that are more akin to classic isolation exercises and rather use mobility movements. For example, I extend my spine with tension and when I cannot go further I relax. Then I flex my spine with tension, when I cannot go any further I will relax. I will repeat this for a few times.
Brad Schoenfeld – http://www.lookgreatnaked.com/blog/light-load-training-can-it-build-muscle/
Dan Ogborn – http://danogborn.com/underestimating-type-i-fibres/
McMasters Study – http://dailynews.mcmaster.ca/article/pumping-iron-lighter-weights-just-as-effective-as-heavier-weights-to-gain-muscle-build-strength/