page 10 | location 145-151 | Added on Tuesday, 23 September 2014 22:14:46 People will see a group of champion swimmers and observe a certain appearance, or they’ll see a group of professional bodybuilders and observe another appearance, and it seems logical to assume that there is something about what these athletes are doing in their training that has created the way they appear. However, this assumption is a misapplication of observational statistics. If you should ever attend a national AAU swim meet and sit through the whole day’s competition, from the initial qualifiers to the finals, you would see these “swimmer’s bodies” change dramatically over the course of the day. This speaks to the fact that it isn’t the activity of swimming, per se, that produces this “type” of body; rather, a particular body type has emerged that is best suited for swimming. In other words, the genetic cream rises to the top through the selective pressure of competition. Competition, it can be said, is simply accelerated evolution.
page 36 | location 542-544 | Added on Wednesday, 24 September 2014 12:29:37 Cooper believed (falsely, as it happens) that the aerobic subsection of metabolism was the most important—more important, in fact, than the totality of metabolic pathways that contribute to human functioning and health. He maintained that this one subsegment of metabolism could and should be isolated and trained. His belief in this regard has since been shown to be without foundation.
page 45 | location 678-684 | Added on Thursday, 25 September 2014 19:32:26 When glucose levels are high and your glycogen stores are completely full, the phosphofructokinase enzyme (which is involved in the metabolism of glucose) gets inhibited. The glucose can now go only to the level of fructose-6-phosphate on the glycolysis cycle, at which point it gets shunted over to the pentose phosphate pathway, which will then convert the glucose, through a series of steps, to glyceraldehyde-3-phosphate (also known as triose phosphate or 3-phosphoglyceraldehyde and abbreviated G3P), which is a fat precursor. Several more metabolic steps are then taken, the end result of which is the production of an energy-bearing chemical called NADH, which is used to fuel fatty acid synthesis. Full glycogen stores, if coupled with elevated carbohydrate levels, actually stimulate the production of fatty acids, particularly in the liver, which drives up the amount of very low-density lipoprotein, because that is the first thing that is converted from glucose to fats.
page 58 | location 885-890 | Added on Thursday, 25 September 2014 22:36:45 In fact, what these designations indicate are the respective fatigue rates of these fibers: there are “slow-fatiguing,” “intermediate-fatiguing,” and “fast-fatiguing” fibers. Even though the force output from fast-twitch fibers is much greater than the force output from slow-twitch fibers, what you will observe on a molecular basis is that the twitch velocity of fast-twitch fibers is actually slower than it is with slow-twitch fibers. Moreover, not only is the twitch velocity slower in fast-twitch muscle fibers, but so is the rate of recovery. The more slowly a muscle fiber fatigues, the more quickly it recovers.
page 60 | location 914-917 | Added on Thursday, 25 September 2014 22:57:39 Consequently, when slow-twitch motor units are triggered, you’re going to be activating somewhere in the neighborhood of 1,000 of them. Fast-twitch motor units, by contrast, are much bigger (you have 10,000 fibers per motor unit), so that when you activate them, you’re going to activate only 50 or 100 of these motor units, because each one of their motor units is so big.
page 77 | location 1168-1171 | Added on Friday, 26 September 2014 23:23:15 The process of growing new muscle can be likened to the process of growing new skin after a burn or a cut. The injury is a stimulus to engage the body’s growth and repair mechanism to heal and repair damaged tissue. The next time you sustain an injury of this type, observe how long it takes your body to produce this new tissue.
page 81 | location 1240-1241 | Added on Friday, 26 September 2014 23:32:27 Since your muscles’ strength changes during contraction, proper strength training must take this factor into account and thus requires a synchronous (or matched) loading (and deloading) of the musculature.
page 81 | location 1231-1234 | Added on Friday, 26 September 2014 23:32:43 In a barbell curl, for example, one might discover that the strength curve of the biceps muscle measures 10 pounds of force when the arm is perfectly straight, 25 pounds of force when the arm is bent 45 degrees, 39 pounds of force when the forearm is bent 90 degrees, 21 pounds of force when another 45 degrees of movement has occurred, and finally, when the hand is at the shoulder, perhaps 12 pounds of force can be produced.
page 132 | location 2022-2025 | Added on Monday, 29 September 2014 21:45:15 All of the aforementioned advice optimally sets the stage for your body to amass the necessary resources to make its adaptive response as stimulated by the workout. Remember that you’re asking your body to make an investment in a tissue that it considers metabolically expensive. If any of these vital points is unaddressed, the reservation of resources for the building of more muscle tissue will inevitably be withheld.
page 172 | location 2630-2633 | Added on Monday, 29 September 2014 22:38:51 In addition to myostatin, there are other genetic determinants of what your response to training might be and your potential muscle size, as well as how specific alterations in a training protocol can be custom tailored to allow these genetic traits full expression. These genetic factors include ciliary neurotrophic factor (CNTF), interleukin-15, alpha-actinin-3, myosin light chain kinase, and angiotensin converting enzyme.6
page 274 | location 4190-4193 | Added on Monday, 29 September 2014 22:39:11 C. E. Stewart and J. Rittweger, “Adaptive Processes in Skeletal Muscle: Molecular Regulators and Genetic Influences,” Journal of Musculoskeletal and Neuronal Interactions 6, no. 1 (January–March 2006): 73–86. This review article nicely covers other genetic factors that control response to exercise and may in the future allow for customization protocols for individuals.
page 186 | location 2841-2844 | Added on Monday, 29 September 2014 23:02:20 Muscle tissue is the most metabolically expensive tissue in the body. You require between 50 and 100 calories a day just to keep a pound of it alive. Let’s assume for a moment that it requires the lower number of 50 calories a day: were you to lose 5 pounds of muscle over time as you perform your steady-state “calorie burning” exercise on the treadmill, that would result in a loss of 250 calories per day that would otherwise be used to keep that muscle alive.
page 193 | location 2955-2963 | Added on Monday, 29 September 2014 23:14:20 When glycogen stores are not full, glucose is moved into the cell for the process of glycolysis to take place. This twenty-step series of chemical reactions gradually converts glucose into pyruvate and then moves the pyruvate into the mitochondria. There it undergoes aerobic metabolism, which produces high levels of ATP, the basic fuel of the body. However, if the body’s glycogen stores are already full when additional glucose attempts to get into the cell, this twenty-step process gets shut down three steps into the gylcolytic pathway. The enzyme at that third step then becomes allosterically inhibitive—changing shape in the presence of high levels of glucose. The process of glycolysis cannot proceed under these circumstances and instead begins to reverse into a process of glycogen synthesis. However, as the glycogen stores are completely full, the glycogen synthesis process arrests, and the glucose is instead moved toward production of a chemical called NADH, which fuels triacylglycerol (or fat) synthesis. The moral of this tale is that insulin levels have to be controlled to create a permissive environment for fat mobilization.