Isometrics - 04 PDF

It should also be said that isometric exercises are more efficient (than dynamic exercises): they produce their effects with a much smaller training effort. -Dr John Atha, Exercise and Sports Science vol. 91...

It should also be said that isometric exercises are more efficient (than dynamic exercises): they produce their effects with a much smaller training effort. -Dr John Atha, Exercise and Sports Science vol. 91 4. Isometric exercise is more efficient than dynamic exercise. Training sessions take less time. Unfortunately, the concept of efficiency is often misunderstood and misused as it applies to resistance training. In the gym or in training articles you might hear or read phrases like; "I don't think the bench press is efficient in building the pecs", or "leg extensions aren't an efficient quad builder". In fact, the authors of these statements are referring to efficacy, not efficiency. An effective exercise is one which produces the desired effect. Efficiency is the quality of producing the desired effect, while avoiding wasted resources (energy, time, etc). An exercise (or training program, or methodology) can be both effective and inefficient. In reality, this is the case with most modern training methods. They get the job done, but with a huge amount of waste. In contrast to most in-gym methods, correct isometric training is the most efficient form of resistance training possible. Understanding why this is, we simply have to clearly understand the concept of efficiency. Efficacy and Henneman’s size principle Based on the above definition, efficiency in training is essentially the ratio of effective training (amount of training effect) to resources used: Energy input Efficiency =------------------- x 100 Training effect  So, what comprises "effective" training? A common way to judge the efficacy of a training method is to look at fiber recruitment. When you want to increase strength or size, your goal should be to recruit as many muscle fibers as possible. This is due to a phenomenon in neurology known as Henneman's size principle, which states that the largest muscle fibers— Type II fibers, those with the greatest capacity to respond with strength or size increases—are always the last fibers in line tc be recruited.^ As a result—whether strength or size is your goal—you need to recruit the maximum number of muscle fibers you can during your training, in order to reach those large fibers. TYPE II FIBERS FAST twitch Strength/power INCREASING FORCE Muscle unit recruitment scheme: Henneman’s size principle Henneman's size principle also states that the only way to recruit more fibers is through higher intensity contractions. Lower intensity contractions—light activities, like jogging or walking—only recruit the smaller fibers, the Type I which are useless for size and strength; they adapt to stress by improving their oxidative metabolism—by gaining stamina (which is why champion marathon runners are never big and strong). Type II fibers, on the other hand, respond to stress by hypertrophy^—these are the fibers you want to recruit if you're interested in getting bigger and stronger.  So maximal fiber recruitment is a good way of judging the efficacy of a resistance training program. Intensity of contraction and fiber recruitment So—just how intensely do your muscles need to contract to maximize fiber recruitment? The answer is: it depends on which muscles you're training. Different muscles possess different ratios of small-to-large fibers. The forearms and muscles of the ankle, for example, have evolved for endurance, thus have more small fibers; as a result, they reach maximal recruitment at lower levels of contraction (because there are fewer large fibers to recruit with bigger contractions). The big workhorse muscles so loved by strength athletes and bodybuilders—the thighs, chest, back and upper arms—have higher ratios of large fibers, and so require higher levels of contraction before maximal recruitment is obtained.^ To give an example, a study published in the journal Brain Research demonstrated that maximal fiber recruitment of the biceps only occurred at 88% of maximal contraction.^ So, using the biceps as an example, our goal in resistance training is at least 88% of maximal contraction to be optimally effective. Anything under 88% and biceps training will not be as effective as it could be. It will still be effective to some degree, it's just that—because energy is being wasted on lower intensity contractions—it is a less efficient way to train. Working at intensities which don't recruit the maximum amount of fibers is analogous to driving a vehicle to a destination in the wrong gear. You'll still get there, but you could've got there faster and with less waste. Contraction-intensity graphs and training efficacy Now we have a concept of what comprises effective training—working at levels of contraction which generate maximal fiber recruitment. How do different methods of training match up to this ideal? First, let's look at an example of isometric biceps training. Let's say an athlete pushes upwards against the Isochain bar and holds it steady in the curl position. He pushes as hard as he possibly can against the bar, for ten seconds.  A 10-second Isochain biceps curl What kind of intensity of contraction is he using? Well, if he is pushing as hard as possible, very quickly it's going to be high as high as he can voluntarily get—easily high enough for maximal muscle fiber recruitmentThis cannot be maintained for long however, because as the athlete tires, he will not be able to contract his muscles as hard. As a result, his contraction­ intensity graph will look something like this:  Force of contraction begins at the highest level and evenly and gradually reduces as the athlete tires. Compare this to the same athlete performing a traditional dynamic exercise, such as barbell curls. We see the same intensity fluctuation we discussed in chapter 3. When you perform a curl, the level of contraction in your muscles fluctuates. At the bottom of the movement, there is virtually no force involved. As you lift the weight, contraction increases due to leverage until your forearms are parallel to the floor, then maxes out; once you pass that point, force decreases, and at the top of the movement, the contraction radically reduces again. When you lower the bar back down, there is less contraction required than at any stage of the upwards movement, because gravity assists.  Barbell biceps curl If we look at this on a contraction-intensity graph, the result looks something like a modified sine wave:  In comparing the two graphs, it's easy to see which form of resistance training is the most efficient. Isometric training, correctly performed, maintains muscular contraction at the highest level possible for as long as possible. By contrast, dynamic training causes intensity of contraction to constantly fluctuate. As a result, a significant portion of training time is spent at low levels of contraction. Why train this way? There really is no reason. Those lower levels of contraction simply represent wasted energy which could better be spent in a target zone of contraction which would recruit and fatigue a greater number of muscle fibers, according to Henneman's principle. Legendary Soviet strength scientist Yuri Verkhoshansky gives us this telling analysis: The (isometric) training is very productive, if the time expended is considered. Each 6-second isometric contraction is equivalent in its effect to many dynamic contractions (of the ballistic type) in which maximal force lasts no more than 0.1 second. From a practical standpoint this means that 10 minutes of isometric tension in specially selected exercises can replace a fatiguing hour of training with weights.^ More efficient training = less training time Remember the difference between efficacy and efficiency which we established at the beginning of this chapter. Nobody is suggesting that an exercise which is five times more efficient than another one will produce five times as much growth, or strength. It simply reduces the waste by a factor of five. In reality, dynamic lifting is effective. Even at sub-maximal levels of fiber recruitment, some strength development or growth takes place—it is simply submaximal. The athlete in our example only spent perhaps two seconds in the maximal contraction position during his curls—compared to ten seconds for the isometric set—but he or she could have easily added more reps or sets to make up the number and induce muscular fatigue. This is exactly how dynamic training proceeds. It does indeed produce results, but it can only do so with the addition of extra sets and repetitions. Many athletes do in fact spend hours in the gym, endlessly grinding their way through lift after lift. Why would athletes continue to waste so much time and effort? Steinhaus, the physiologist who brought German isometric research to the West in the 1950s, contended that the reason athletes sometimes balked at isometrics was psychological—not biological. He thought that athletes had been taught to suffer, and that any system which made training seem easier felt "wrong" to them—even if it was rights In his classic book Physiology of Muscular Activity, sports ideologist P. V. Karpovich made the following observation on the startling results of isometric strength training: It is hard to accept these reports, because they apparently contradict everyday experience. Just think about musclemen working one to two hours per day for at least three days per week in order to develop strength. Maybe they are Just wasting their time. Maybe.® Isometrics is the most efficient form of resistance training on the planet. Even a quick glance at the contraction-intensity graphs of isometric and dynamic exercises proves that it is mathematically impossible for dynamic exercises to train the muscles as efficiently as isometrics. Because no time (or energy) is wasted performing sub-maximal contractions, the time taken to perform a set is radically reduced. Training volume—the number of sets—is also reduced. As a result, training time is significantly reduced while performing isometrics compared to traditional dynamic methods. In fact, as Verkhoshansky confirms, isometric programs can work the entire body in as little as ten minutes—compared to 45 minutes to an hour for the dynamic equivalent.