Feeding the Female Athlete:Nutritional requirements for strength-training women by Jerry Brainum

A recently published comprehensive review examined the nutritional requirements of women who regularly engaged in bodybuilding, powerlifting and/or weightlifting. While many of their nutritional requirements are similar to those of men, there are a few notable differences.
    Women often initially show greater strength gains because they’re usually weaker than men at the start of a training program. Another obvious difference between the sexes is the ultimate degree of attainable muscle size. Because of both structural and hormonal differences, the average man can develop far larger muscles than the average woman. That’s most often attributed to men’s higher level of testosterone. Women won’t develop a masculine body shape—unless, of course, they use testosterone-based drugs and other anabolic substances associated with muscle bulk. (The fact that women respond to such drugs is evident from the appearance of some competitive female bodybuilders, whose muscular size far exceeds what could be developed through natural means.) Women who choose the natural route can still attain a significant loss of bodyfat and muscular definition, though it’s admittedly an uphill battle in comparison to males because a woman’s hormonal profile—higher estrogen, lower testosterone—tends to favor fat accretion, especially in the lower body and just under the skin.
    From the standpoint of exercise metabolism, women show a clear superiority in fat use over men—again, likely the result of higher estrogen. When engaged in exercise, women can tap into fat stores more efficiently and rapidly than men. The performance gap between men and women is far less significant in endurance than strength sports.
     Women store higher levels of fat in muscle, known as intramuscular triglyceride. IMTG is believed to be related to a woman’s higher percentage of slow-twitch muscle fibers, also known as “endurance” fibers, which preferentially burn more fat during activity and at rest. Studies of endurance exercise show that women tap into IMTG at greater levels than men.
    The greater use of fat spares muscle glycogen, which is stored carbohydrate, an effect that extends to weight training, with women using more fat and less glycogen. It’s attributed to a lower activity of the glycolytic enzymes in muscle that activate muscle glycogen breakdown, which may be due to higher estrogen levels.
     Because of their concern with appearance, many women overly restrict calorie intake, which some studies show can work against elite female athletes. Overly restricting calories leads to a lower metabolic rate, which paradoxically increases bodyfat levels. A low energy intake also leads to fatigue, irritation and decreased performance—as it does in men.
     Women who don’t eat enough show decreased thyroid hormone activity, which not only depresses fat losses but also results in lower energy. Bone mass, fertility and creatine replenishment in muscle are also adversely affected. Not consuming enough food increases the risks of nutrient deficiencies.
Since weight training increases resting metabolic rate for up to 36 hours, women should get most of their calories before and after training. That keeps calories from shifting to bodyfat stores. From a practical standpoint, women engaged in weight training need to eat 39 to 44 calories per kilogram of bodyweight daily. Health and energy problems occur if an active woman’s total daily calories drop below 1,800.
     Studies confirm that women handle carbohydrates differently than men. Women not only use less glycogen during training but also synthesize less after a workout. To synthesize more glycogen following training, a woman must take in up to eight grams of carbohydrate per kilogram of bodyweight. That much carb, however, would use up a large percentage of her daily calories.
    Women do need carbohydrates for purposes of glycogen replenishment following training, but they don’t need to eat like endurance athletes. The best type of carbs are those with a low-glycemic rating, meaning that they provide a slower delivery of carbs into the body, favoring less fat synthesis. Foods high in fiber have lower glycemic index numbers—fruits, vegetables, brown rice, whole-grain breads, oatmeal, beans, legumes and sweet potatoes. Cruciferous vegetables, such as broccoli, brussels sprouts, kale, cabbage and bok choy, are particularly beneficial for women because they contain natural elements that lower excessive estrogen levels, thus helping women lose superfluous water and fat.
     Studies show that men burn more protein during training than women do. Women’s higher use of fat during exercise may provide a sparing effect on protein, as well as glycogen. On the other hand, studies also show that women are less efficient than men in promoting muscle protein synthesis after training. That points to a need to get more protein at that critical time. For building lean mass, women are advised to eat small amounts of high-quality, rapidly digested protein with some carbohydrate before and after exercise and between meals to maintain an optimal anabolic metabolic environment.
    Women are also advised to ignore the myths about high-protein diets, among them that eating a lot of protein leads to bone loss and osteoporosis. Studies show an opposite effect: A higher protein intake promotes bone mass. Some high-protein foods also provide nutrients essential to bone formation and maintenance, such as calcium, magnesium and vitamin D.
     Some women espouse vegetarianism in the belief that it’s both healthier than eating meat and favors less bodyfat. While it’s indeed possible to maintain health while forgoing animal proteins, that’s not ideal for bodybuilding. Women need to pay special attention to iron intake, since they’re more at risk for anemia. Meat contains the most easily absorbed source of iron, heme iron, while the iron contained in plant sources often isn’t as available, due to iron-blocking substances in plants, such as oxalate and phytate. Animal proteins also provide such vital nutrients as B-complex vitamins and minerals. Women who are worried about the fat content of meat can take a high-quality protein supplement such as whey and/or casein, which will be devoid of fat and carbs.
    Some women may also be overly concerned about fat, thinking that eating fat promotes bodyfat. A suitable fat intake helps replenish the intramuscular fat stores that women tap into during exercise, which also spares their limited muscle glycogen stores. Women should get 30 percent of their daily calorie requirement from fat to replenish depleted IMTG stores. If they don’t get enough dietary fat, those muscle fat stores can remain depleted for two days after training, adversely affecting exercise ability.
     Dietary fat is also required to maintain sex hormone function in women, just as it is in men. If a woman doesn’t eat enough fat, she’ll likely experience menstrual disturbances. Getting less than 15 percent of calories from fat also increases the risk of an essential fatty acid deficiency, which can result in diminished fat burning in addition to serious health problems.
   Dietary fats should come from lean protein foods, nuts, seeds, fatty fish such as salmon (or fish oil supplements for omega-3 if you hate eating fish), as well as flaxseed, safflower, canola and extra-virgin olive oils. Avoid trans fats—also known as partially hydrogenated fats—which favor bodyfat, cancer and cardiovascular disease, in addition to amino acid loss in muscle. Eating healthful fats permits a lower carb intake, favoring better body composition for female strength athletes.
    Women respond to most supplements like men. Creatine works well, although it doesn’t block protein oxidation as it does in men. It’s a moot point, though, since women burn less protein than men during exercise anyway. Women should also avoid all types of testosterone-boosting supplements, including the estrogen blockers. Such supplements are great for men, but in women they can create serious hormonal disturbances.
    DHEA acts as a hormone precursor in both men and women. In men it tends to convert into estrogen, but in women it always converts into testosterone. While that initially sounds good for female strength athletes, many of them have developed serious cases of acne when taking DHEA. That’s not so surprising if you consider that the DHEA spurt in teenagers of both sexes is what causes acne. A form of DHEA that doesn’t convert into sex hormones, 7-keto DHEA, is also available in supplement form. It may help prevent dieting plateaus by maintaining thyroid output, but it’s free of the adverse effects associated with regular DHEA.
Add it up, and it’s clear that women strength athletes should reduce carbohydrate intake in favor of “good” fat sources while increasing their protein, especially after training. Doing so ensures great progress while maintaining energy and health.   

Volek, J.S., et al. (2006). Nutritional aspects of women strength athletes. British J Sports Med. 40:742-48.




©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

Have you been ripped off by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Jerry Brainum's book Natural Anabolics, available at JerryBrainum.com

 
 

The Applied Ergogenics blog is a collection of articles written and published by Jerry Brainum over the past 20 years. These articles have appeared in Muscle and Fitness, Ironman, and other magazines. Many of the posts on the blog are original articles, having appeared here for the first time. For Jerry’s most recent articles, which are far more in depth than anything that appears on this blog site, please subscribe to his Applied Metabolics Newsletter, at www.appliedmetabolics.com. This newsletter, which is more correctly referred to as a monthly e-book, since its average length is 35 to 40 pages, contains the latest findings about nutrition, exercise science, fat-loss, anti-aging, ergogenic aids, food supplements, and other topics. For 33 cents a day you get the benefit of Jerry’s 53 years of writing and intense study of all matters pertaining to fitness,health, bodybuilding, and disease prevention.

 

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Muscle Destruction From Steroids, and how Nolvadex really works by Jerry Brainum

Anabolic steroids are synthetic, structurally modified versions of testosterone. They are termed “anabolics” because they provoke reactions in muscle and other tissues that result in either growth or stabilization of the tissues. Anabolic steroids have legitimate medical uses, such as preventing excessive tissue breakdown. Athletic use of steroids, however, is far more publicized than their medical applications. Bodybuilders and other athletes who use anabolic steroids often self-medicate with dosages far above what medical treatment requires. In line with the adage “Only the dose determines the poison,” those using large doses of steroids or several of the drugs simultaneously can be subject to systemic side effects: liver problems, negative changes in blood lipids and heart structure, fluid retention, gynecomastia in males, virilism in women, inhibition of testosterone production and possible adverse behavioral changes in susceptible individuals.
     While all of those side effects are possible in theory, in reality they rarely occur. Athletes monitor themselves for adverse effects, although rarely under the care of a physician. They use other drugs to mitigate some of the side effects of large doses, such as estrogen-blocking drugs to prevent estrogen-related side effects.
      Idiosyncratic reactions, however, are always possible. That means some steroid users experience unusual or rare side effects. Why that happens is unknown but probably has something to do with genetics or individual susceptibility. One recent case study illustrates the point.
      A 39-year-old previously healthy amateur bodybuilder reported to an emergency room with excruciating pain and inability to move his right shoulder after an injection of steroids in that shoulder, which was followed by a shoulder workout on the same day.¹ He trained five days a week and had done so for the previous eight years. For the past seven years he had also used anabolic steroids. Deploying a 23-gauge needle and sterile technique, he injected steroids into his shoulder four times a week. He denied doing any type of abrupt overstretching exercise that could have caused a severe muscle strain.
    The physical exam showed that his right deltoid was swollen and tense, with the skin around it red, tender and warm. He had no apparent bruising and no fever. The picture became clearer when blood tests revealed a creatine kinase enzyme level of 18,200—normal is below 195. Creatine kinase is an enzyme that adds a phosphate to creatine in muscle, thereby helping the muscle store creatine. When muscle is damaged, even with intense exercise, CK is released from the muscle into the blood. Having large amounts in the blood point to severe muscle damage. Because the bodybuilder’s blood potassium, also released by damaged muscle, was high, the diagnosis was rhabdomyolysis, which means massive muscle destruction.
     Rhabdomyolysis can have several causes, among them toxic reactions, lack of blood flow to muscle, infections and inflammation. One type, which is called exertional rhabdomyolysis, occurs when muscle cells are damaged by unaccustomed exercise. For example, untrained persons who exercise in hot, humid weather can develop it, but it can also occur in well-trained athletes. Switching to a new mode of intense training without preparation can bring it on. A few cases have occurred in bodybuilders who abruptly began high-rep—100 reps or more per set—training regimens, particularly in hot weather without drinking adequate fluids.
     Destruction of the muscle cell membrane causes the leakage of intramuscular materials, such as CK, minerals and other enzymes. In severe cases myoglobin, the oxygen-carrying protein in muscle, is also released in large amounts and can crystallize in the kidneys. That blocks the kidneys’ filtering units and rapidly induces kidney failure. Without immediate treatment, death follows.
    Several cases of exercise- or drug-related rhabdomyolysis in long-distance runners, football players and military personnel have been reported in the medical literature. One published case study involved a 25-year-old male professional dancer who showed up at a hospital complaining about severe thigh and calf pain.
     The pain began after he engaged in a 45-minute aerobic workout on a cross-training machine. He experienced severe muscle cramps and a day later showed up at the hospital. He was given an anti-inflammatory drug but returned two days later, still in severe pain. Tests revealed a high CK level, which led to a diagnosis of rhabdomyolysis. He received intravenous fluids and buffers such as potassium bicarbonate to alkalinize his blood and prevent myoglobin precipitation in the kidneys. He received cortisone to relieve inflammation, Valium to relax his muscles and Tylenol for pain.
     The dancer had used two steroid drugs, Winstrol and Primabolan, four ampoules each a week apart. Before his pain set in, he’d used only one ampoule of Primobolan a few days before, injecting it into his thigh. His treatment proved successful, and he was released from the hospital.
     Reports involving bodybuilders have been sporadic and may have been written off as severe muscle strains. One 40-year-old bodybuilder who initially denied using any anabolic steroid or other drugs suffered rhabdomyolysis in his biceps. In fact, he’d also injected Winstrol into the affected shoulder, leading the attending physicians to suspect that the injection itself had caused the localized rhabdomyolysis. The doctors suggested that he might have had a toxic reaction to the drug—a not unwarranted assumption, as most forms of injectable Winstrol are veterinary versions not subject to the same quality control as drugs slated for human use. A more likely possibility is that the bodybuilder had a compartment syndrome, the name given to a swelling of the fascia that surrounds muscle. Usually occurring in the calf, it’s rare in the shoulders because of the higher mobility of the shoulder and its attendant fascia. Only three previous cases were reported in the medical literature, and they involved drug overdoses or intoxication after minor trauma.
    The analysis was that the bodybuilder suffered increased compartment syndrome due to the injected fluid, causing a blood clot, which decreased the elasticity in the shoulder fascia. Compounded by the bodybuilder’s growing shoulder muscle mass, those factors increased the intracompartmental pressure. The shoulder workout that followed amplified the effect of limited blood flow, which resulted in the characteristic muscle breakdown. His treatment proved successful, and he returned to normal training with no evidence of kidney problems.

                                                 How Nolvadex Really Works

Tamoxifen citrate, or Nolvadex, is used to treat breast cancer, particularly in older women who have estrogen-sensitive breast cancer; 70 to 80 percent of all breast cancers are estrogen-sensitive. For years it’s also been used by male bodybuilders on anabolic steroids to help prevent gynecomastia, or the formation of male breast tissue.
    Gyno is caused by an imbalance between estrogen and testosterone, favoring increased estrogen. The steroid drugs convert into estrogen through the actions of aromatase, an enzyme found throughout the body. The usual practice for preventing estrogen-related side effects, which include excess water and fat retention, is to take drugs that either interfere with aromatase activity, such as Arimidex, or block estrogen cell receptors, such as Nolvadex.
     Nolvadex is the older of the two “estrogen solutions,” and most athletes looking to lower estrogen now rely on aromatase-inhibitors because of the notion that they’re more reliable in diminishing estrogen. Nolvadex is also thought to interfere with the activity of growth hormone and its anabolic product, insulinlike growth factor 1. On the other hand, lowering estrogen too much, which is possible with extended use of aromatase inhibitors, may interfere with the anabolic reactions involving androgen receptors and testosterone.
Nolvadex is structurally similar to estrogen and can bind to estrogen cell receptors, thereby blocking estrogen from binding to them. If estrogen cannot interact with its cellular receptors, it cannot exert biological activity and becomes inert. Nolvadex also interferes with the negative feedback signal sent by circulating estrogen in the blood to the pituitary gland. That results in blunting release of gonadatropins, including luteinizing hormone, which controls testosterone synthesis at the Leydig cells in the testes. The reduced estrogen-feedback signal induced by Nolvadex results in greater release of luteinizing hormone and higher blood testosterone. One author has noted that using 20 milligrams of Nolvadex daily—a standard bodybuilding dose—can raise blood testosterone by 150 percent. On the other hand, Nolvadex has both agonist and antagonist properties. That is, when used in high doses for extended times, it may act more like an estrogen agonist. Animal studies show that extended use of Nolvadex interferes with the activity of two testicular enzymes involved in testosterone synthesis, although that hasn’t been confirmed in human studies.
    What’s interesting about Nolvadex is that recent research that directly compared it to the newer and supposedly more effective aromatase-inhibiting drugs found that Nolvadex appears to be more effective in preventing gynecomastia and other estrogen-related effects in men. How can that be?
    A study presented at a scientific conference related to breast cancer research may provide the answer. Researchers from the famed Mayo Clinic explained that Nolvadex isn’t active but is rather like a pro-hormone. In the liver, enzymes convert Nolvadex into two metabolites that are the effective versions of the drug, endoxifen and 4-hydroxytamoxifen. The study sought to explain why using Nolvadex helps some women with breast cancer but not in others. The researchers found that an enzyme system in the liver called CYP2D6 must convert Nolvadex into its active metabolites in order for the drug to work. In some women that system isn’t as active, which means that they don’t convert the Nolvadex into its most active metabolite, endoxifen. For them Nolvadex doesn’t effectively treat breast cancer.
     Most surprising, however, was the finding that endoxifen didn’t just block the estrogen cell receptor, as was previously supposed, but actually degraded it. No receptor means no estrogen cell activity. So drug researchers are now at work producing a direct endoxifen drug, since that’s the actual active form of Nolvadex. The direct form won’t depend on liver enzymes to become active.
     While this study involved in vitro, or isolated-cell, protocols, there is no reason to believe that the results don’t apply to men. The findings explain why Nolvadex works better in preventing estrogen-related side effects in some men more than others. In addition, the fact that this active metabolite of Nolvadex actually degrades estrogen receptors explains why the head-to-head studies comparing Nolvadex to aromatase inhibitors showed Nolvadex to be superior in preventing estrogen-related side effects in men. A notable bonus: Nolvadex is far less expensive than most aromatase inhibitors.

References

1 Farkash, U., et al. (2009). Rhabdomyolysis of the deltoid muscle in a bodybuilder using anabolic-androgenic steroids: A case report. J Athlet Training. 44:98-100.
2 Adamson, R., et al. (2005). Anabolic steroid-induced rhabdomyolysis. Hosp Med. 66:362.

 
 ©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

Have you been ripped off by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Jerry Brainum's book Natural Anabolics, available at JerryBrainum.com

 
 

The Applied Ergogenics blog is a collection of articles written and published by Jerry Brainum over the past 20 years. These articles have appeared in Muscle and Fitness, Ironman, and other magazines. Many of the posts on the blog are original articles, having appeared here for the first time. For Jerry’s most recent articles, which are far more in depth than anything that appears on this blog site, please subscribe to his Applied Metabolics Newsletter, at www.appliedmetabolics.com. This newsletter, which is more correctly referred to as a monthly e-book, since its average length is 35 to 40 pages, contains the latest findings about nutrition, exercise science, fat-loss, anti-aging, ergogenic aids, food supplements, and other topics. For 33 cents a day you get the benefit of Jerry’s 53 years of writing and intense study of all matters pertaining to fitness,health, bodybuilding, and disease prevention.

 

See Jerry's book at  http://www.jerrybrainum.com

 

Want more evidence-based information on exercise science, nutrition and food supplements, ergogenic aids, and anti-aging research? Check out Applied Metabolics Newsletter at www.appliedmetabolics.com

 

Growth Hormone Muscle Zone by Jerry Brainum

Bodybuilders and other athletes speak of growth hormone with hushed reverence. Many think that GH is what’s primarily responsible for the massive physiques that dominate professional bodybuilding today and that seem to dwarf those of a generation ago.
    While it’s true that GH is one of three primary anabolic hormones in the body (the others being testosterone and insulin), it’s also true that GH is shrouded by myth. Take the notion that using a pharmaceutical form of GH enables you to eat as many as 10,000 calories a day yet lose appreciable levels of bodyfat simultaneously. Another idea is that GH promotes hyperplasia, or a splitting of muscle fibers into new fibers—a property that other anaboliic hormones don’t have.
    The reality about GH is not quite so dramatic. The only drug-tested Mr. Olympia occurred in Chicago back in 1990. Several of the competitors told me, off the record, that they planned to circumvent that year’s drug prohibition by using large amounts of GH. Then, as now, there was no official test to show that an athlete was injecting GH. The competitors figured that GH provided little or no actual anabolic or muscle-building effects by itself but did pack a punch when used with anabolic steroids. When the steroids were eliminated a few weeks before the contest, GH froze the muscle size produced by the earlier drug cycles and kept delivering fat-loss benefits.
     That makes a lot of sense because GH is a survival hormone. Among its many functions is that it preserves lean mass, mainly muscle, by promoting the use of bodyfat as fuel. GH also comes into play as a counter-regulatory hormone to insulin. When insulin lowers blood glucose, GH and other hormones prevent the levels from dropping too low. The antagonist effect of GH against insulin is so potent that many researchers believe that large doses of it promote insulin insensitivity, thus increasing the chance for diabetes. More recent studies, however, show that normal levels of GH, such as that induced by exercise, help prevent both metabolic syndrome and diabetes by cutting visceral, or deep-lying, abdominal fat.
     The anabolic reputation of GH has also fostered a large response from the food supplement industry. Most GH supplements on the market are based on various combinations of amino acids. Whether aminos actually promote a GH response depends on how and when they’re used. Intravenous administration of the amino acid arginine in 30-gram doses promotes significant GH release unless you’re deficient in the hormone or have defective hormone release mechanisms.
    When it’s taken orally, however, the scenario changes. Arginine goes to the liver, where it encounters the enzyme arginase, which degrades it. You could get around the formidable enzymatic barrier by increasing the oral dose, but then you’d probably have to deal with nausea. Besides, when you take arginine prior to weight training, it has the paradoxical effect of blunting GH release.
     Several studies have shown that a drug form of GH combined with exercise offers no advantages over exercise alone. On the other hand, the GH release produced by exercise does offer several significant effects for bodybuilding purposes. An increase in GH, coupled with the rise in other anabolic hormones, improves muscle protein synthesis. That translates into increased muscle size and strength. The actual anabolic effector is insulinlike growth factor 1, which is produced in the liver under the stimulation of GH release.
The IGF-1 produced in the liver is used throughout the body. IGF-1 is also produced locally in trained muscle, often as a result of damage from intense exercise. That IGF-1 is used for muscle repair and promotes the activity of muscle stem cells, or satellite cells. Locally produced IGF-1 is further spliced into two variants in muscle, with one being the mechano growth factor, or MGF, probably the most anabolic substance of all because it directly controls the activity of muscle satellite cells. MGF is so potent that it can resuscitate dying satellite cells in older animals and people.
     If providing GH alone doesn’t do much for muscle growth, and considering that IGF-1 and MGF are the primary anabolic growth factors in muscle, why be concerned about promoting GH release through exercise?
One reason is the size-and-strength synergy of GH, testosterone and insulin. Each hormone appears to potentiate the anabolic effects of the others. They’re synergistic in another sense too. A high level of GH offsets the possible side effects of other anabolic hormones. For example, by itself insulin is the greatest promoter of increased bodyfat synthesis. It also lowers blood glucose, leading to a loss of training energy and increased fatigue. GH and, to a lesser extent, testosterone counteract insulin’s bad side.
Of the three major anabolic hormones, GH provides the most potent fat mobilization, especially for people on low-carbohydrate diets who exercise. GH is secreted most substantially when blood glucose and fat levels are lower and amino levels are higher—conditions typical of people on low-carb diets.
     One reason it’s so hard for people who have a lot of bodyfat to lose weight is that they usually have higher resting insulin levels. That opposes GH release. When they begin to exercise, their normal GH release response is also blunted, making fat loss an arduous process. The good news is research showing that losing bodyfat through regular diet and exercise normalizes the GH response to exercise.
    Another reason you want to promote a GH response during exercise is that GH is uniquely useful for preserving and repairing connective tissue, such as ligaments and tendons. Anyone who’s lifted for any length of time knows well the training setbacks caused by connective-tissue injuries. Connective tissue, unlike muscle, has a poor blood supply, so healing injuries can take weeks or even months. GH strengthens and repairs connective tissue, accelerates its healing and prevents the damage from occurring in the first place.
That helps explain why so many world-class athletes use GH, even if they aren’t interested in building massive muscles. GH helps them recuperate from intense training and protects connective tissue from injury.
GH’s role in protecting connective tissue also applies to people as they age. Most forms of joint pain involve connective tissue and often appear when GH levels drop with aging. Paradoxically, injecting large doses of GH causes joint pain in many people through an overgrowth of tissue.
     One interesting aspect of exercise and GH is that normally when large amounts of GH enter the blood, the brain’s feedback system blunts release of the hormone that releases GH. Yet with continued exercise, the body overcomes the feedback.
     As to what precisely sets off GH release during exercise, scientists still aren’t sure. There are, however, several candidates.One theory is that exercise-induced muscle tension provides a neural effect, leading to a GH release. Another popular hypothesis is that nitric oxide stimulates GH release during exercise. Studies show that NO does potently promote GH release, but they involved isolated cells, and whether the effect occurs in a living human body is still speculative.The most popular explanation is that the hydrogen ions, or acid produced in muscle, relay a chemical message to the brain that results in a heightened GH response. When subjects take antacids, such as sodium bicarbonate, during exercise, the GH release is blunted.
That raises the question of whether using supplements that reduce muscle acidity, such as beta-alanine, would reduce GH release. The answer is no; supplements work in the muscle, and the acid feedback mechanism that stimulates GH release occurs in the blood.Thus, ingesting sodium bicarbonate, or baking soda, which has an alkalizing effect on blood acidity, would likely blunt GH release if ingested prior to physical activity.
    So what type of exercise promotes the greatest GH release? The short answer is the kind that’s brief, hard and intense. Lifting weights would get more results than most aerobic workouts. To get a GH response from aerobics requires passing what exercise scientists refer to as the lactate threshold—when lactic acid appears in the muscle. That event signals a change from aerobic to anaerobic exercise metabolism. While doing high-intensity aerobics, such as interval training, promotes higher GH release, it also lowers the fat oxidation that occurs during lower-intensity aerobics. Interestingly, doing high-intensity aerobics increases resting pulse amplitude of GH release, meaning that you burn more fat at rest. That may help explain why interval training leads to greater fat loss than conventional steady-state aerobics.
    Early studies suggested that you can achieve the greatest GH response from exercise that you do several times a day. More recent studies, however, demonstrate that you get the greatest effect from the initial workout, with workouts done later on the same day leading to blunted GH release. That’s because the workout stimulates higher blood lipids, which persist for several hours afterward. Higher blood fat blunts further GH release during exercise.¹
    The more muscle you use during an exercise, the greater the release of GH. So training larger muscle groups, such as the legs and back, produces a far greater GH release than training smaller muscle areas, such as arms or shoulders. Aerobic equipment that involves both upper- and lower-body muscles simultaneously stimulates higher GH levels than lower-body-only exercises or machines.
    One reason exercise promotes GH release is that it usually raises core body temperature. GH regulates body temperature and helps prevent overheating during exercise. Conversely, exercising in the cold inhibits the release of GH.² So, for example, rowers have higher levels of GH than swimmers, whose core temperature goes down because they’re in the water.
    Eating a high-fat meal prior to training blunts GH release. So will eating carbs, but to a lesser extent.³ Some studies show that having a protein-and-carb drink before and after training leads to a greater GH release, though other studies haven’t substantiated that. Using asthma drugs in the category of beta-2 agonists also blunts GH release during exercise—that includes the drug clenbuterol. Researchers think that’s because the drugs increase the release of somatostatin, a protein that blocks GH. Even not drinking enough water during training blunts GH release.⁴
     GH response is greater when you do multiple sets than when you do single sets. One study showed a greater GH response among exercisers doing four sets than those doing two, but doing six had no further effect. Another study showed that doing forced reps increased GH release.
Doing a high-rep set at the end of a series of heavier sets also produces a much greater GH release, as does resting one minute or less between sets. Lowering the weight (eccentric or negative reps) produces greater GH release than raising the weight.⁵
   Since most scientists agree that GH and IGF-1 drop precipitously with age and that the lack of those hormones produces many symptoms associated with aging, continuing to engage in exercise known to elicit the greatest GH response can produce a reliable antiaging affect. It’s likely that the true advantages of weight training will manifest themselves in the realm of longevity and quality of life.

References

¹ Stokes, K., et al. Human growth hormone responses to repeated bouts of sprint exercise with different recovery periods between bouts.J App Physiol. In press.
² Wheldon, A., et al. (2006). Exercising in the cold inhibits growth hormone secretion by reducing the rise in core temperature. Growth Hor IGF-1 Res.16:125-31.
³ Cappon, C.P., et al. (1993). Acute effects of high-fat and high-glucose meals on the growth hormone response to exercise. J Clin Endocrin Metabol. 76:1418-22.
⁴ Peyreigne, C., et al. (2001). Effect of hydration on exercise-induced growth hormone response. Eur J Endrocrin. 145:445-50.
⁵ Kraemer, W.J., et al. (2005). Hormonal responses and adaptations to resistance exercise and training.Sports Med. 35:339-61.
 




©,2012, Jerry Brainum.Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

Have you been ripped off  by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Jerry Brainum's book Natural Anabolics, available at JerryBrainum.com.

 

The Applied Ergogenics blog is a collection of articles written and published by Jerry Brainum over the past 20 years. These articles have appeared in Muscle and Fitness, Ironman, and other magazines. Many of the posts on the blog are original articles, having appeared here for the first time. For Jerry’s most recent articles, which are far more in depth than anything that appears on this blog site, please subscribe to his Applied Metabolics Newsletter, at www.appliedmetabolics.com. This newsletter, which is more correctly referred to as a monthly e-book, since its average length is 35 to 40 pages, contains the latest findings about nutrition, exercise science, fat-loss, anti-aging, ergogenic aids, food supplements, and other topics. For 33 cents a day you get the benefit of Jerry’s 53 years of writing and intense study of all matters pertaining to fitness,health, bodybuilding, and disease prevention.

 

See Jerry's book at  http://www.jerrybrainum.com

 

Want more evidence-based information on exercise science, nutrition and food supplements, ergogenic aids, and anti-aging research? Check out Applied Metabolics Newsletter at www.appliedmetabolics.com

 

The science of muscle growth by Jerry Brainum

What makes muscles grow? The obvious answer would be intense exercise and good nutrition, with enough rest and recuperation to maximize size and strength gains. The reason lifting weights produces greater gains in muscle size and strength is that it places more stress on the muscles compared to other types of exercise, such as stretching or aerobics. The muscles respond to the stress through adaptation, involving upgraded muscle protein synthesis.
     That’s the general picture of what causes muscle growth. What happens in the muscle after exercise is a much more complex picture. On a molecular level, muscle growth is a precise symphony involving the immune system, inflammation, hormone release and structural changes. While the knowledge of what’s happening in a muscle during and after training may seem superfluous to anyone except a research scientist, a rudimentary understanding of the internal workings of exercised muscles can tell you what constitutes correct training and rest cycles for gains in size and strength.


                             What Is Muscular Hypertrophy?

      The term hypertrophy means “excessive growth,” and in reference to muscles, that means enlarged muscles usually acquired through exercise. An ongoing debate in physiology is whether muscles get bigger through the addition of new fibers—a process called hyperplasia through which existing muscle fibers split to form new fibers—or whether muscles grow by thickening existing fibers. The fiber-thickening scenario is the generally accepted view.
      Some studies comparing world-class bodybuilders to untrained college students showed that both groups’ muscle fibers had similar dimensions when viewed under a microscope, though the bodybuilders clearly had much larger muscles. Later studies showed that the bodybuilders had far more muscle fibers than untrained college students. The speculation is that years of intense, heavy training promote hyperplasia of muscle fibers.
      Muscle size is related to the cross-sectional area of muscle fibers, or their thickness. As the muscle fiber thickens from a compensation effect induced by heavy exercise, the muscle gets bigger and stronger. Big muscles aren’t always stronger muscles, however. What determines muscle strength is a combination of factors, including favorable leverage and connective tissue. Most important is the increase in muscle contractile proteins, specifically actin and myosin. Some pathological conditions feature large but, paradoxically, weak muscles. An example is acromegaly, usually the result of a small tumor in the anterior pituitary gland that causes the release of huge amounts of growth hormone. People suffering from the disease from an early age wind up very tall, with larger but weaker muscles.
       Indeed, the majority of studies examining the athletic use of growth hormone injections conclude that the drug promotes larger muscle size but without an accompanying increase in strength. GH promotes connective tissue increase in muscle but doesn’t affect the muscle contractile proteins that are the cornerstone of muscular strength.

                      Satellite Cells: The Inner Space of Muscles

     Satellite cells are so named because of their location on the outer surface of the muscle fibers, between the muscle cell membrane, or sarcolemma, and uppermost layer of the basement membrane, or basal lamina. Satellite cells are muscle precursors, or a type of stem cell, that usually lie dormant outside existing muscle fibers. They become activated when any form of trauma, such as damage or injury, occurs to a muscle fiber.¹ Resistance exercise, as exemplified by weight training, causes damage to muscle fibers, which deal with it by marshaling adaptation mechanisms, the most significant being activation of satellite cells.
     The damage causes satellite cells to multiply, and various other factors, as we’ll see, cause them to migrate toward the injured area. The satellite cells then fuse to the injured area, while adding a nucleus to the existing fiber, which aids the regeneration process. That doesn’t add new muscle fibers but instead leads to an increase in the amounts of contractile proteins—the actin and myosin—within the fiber. The net effect is muscular growth and strength. The process peaks at 48 hours but continues for four days after the initial trauma (exercise) occurs. That’s why you need time to let a muscle recover after a training session.
      Two main types of muscle fibers are found in humans. The first are known as type 1, or slow-twitch, fibers, also called endurance fibers because of their capacity for extended exercise, such as long-distance running. The other type of muscle fiber, type 2, or fast-twitch, are much larger than the type 1 fibers. They have less endurance but can exert more force, an effect thought to be related to their having a larger nerve supply. Type 2 fibers are most amenable to gains in muscular size and strength, so you’d think they’d have a larger supply of satellite cells around them. In fact, the type 1 fibers have five to six times more, which may reflect their greater blood and capillary supply. (Some studies, however, show an equal number of satellite cells in both types.)
     Another reason for the plethora of satellite cells in type 1 fibers is that they’re used more frequently than type 2s. Muscles function through an orderly recruitment system, and the body attempts to husband its limited energy by activating only enough muscle to do the required task. The first fibers recruited are type 1s, and so they’re subject to a greater rate of injury than the type 2s. As type 1 fibers become fatigued or get stressed by mass or weight, the brain recruits the type 2 muscle fibers. That explains why you need to lift heavy to make maximum gains in the gym. Lifting light weights for higher reps recruits the type 1 fibers, which, as noted, are less likely to get bigger and stronger.
       Most people over age 40 will tell you that it’s harder for them to make significant gains in muscle size, even with regular training. One reason is a relative lack of testosterone, a hormone required for building muscle. The level of testosterone that physicians call “normal” is okay for everyday life, but having a blood testosterone level lower than 300 makes gains in the gym unlikely at best.
     Another reason for the slowdown of muscle gain with age is a loss of neuromuscular efficiency: The muscles become less responsive to the cues from the brain. Without the optimal level of nerve force, a muscle cannot contract as forcefully, and the net effect is a loss of speed, size and strength. Lessened nerve force is usually the reason illustrious athletic careers end. The muscles may still be in relatively good shape, but the response systems are delayed.
     Those over 40 also find that it takes longer to recover from training sessions. Connective tissue, such as ligaments and tendons, has a far poorer blood supply than muscles, which is why connective tissue injuries take longer to heal. With age such tissues get dryer, leading to an even longer recuperation time. Since connective tissue plays a role in muscle strength, if you attempt to train too much or too frequently, you won’t make any gains and will feel overtrained.
      People 40 and older often have fewer satellite cells than younger people—40 percent less relative to the total number of muscle nuclei. Since you need satellite cells to repair damaged muscle, the significance of the loss is obvious; however, it may not be as extreme in those with a long history of training. One study of powerlifters found that the satellite cell content of their trapezius muscles was 70 percent higher than that of nonexercising subjects. ²  The study also featured powerlifters who were taking anabolic steroids, and their level of satellite cells was similar to that of the “clean” lifters.
     Recent studies show that while heavy resistance exercise is the best way to recruit and activate satellite cells, endurance exercise can also increase satellite cell activity. A study of older men involved in endurance exercise without weight training showed that they had a 29 percent increase in satellite cell activity.³ What ultimately determines satellite cell activation is the extent of muscle fiber damage. As you might expect, satellite cell numbers decrease—gradually but regularly—when training ceases. Training enables satellite cells to constantly renew themselves.

                           What Stimulates Satellite Cells?

    Clearly, exercise activates satellite cells. Other factors help maximize the effect. The initial localized inflammation is necessary for containing and repairing the damage, as well as attracting the immune cells, or macrophages, that sweep the area of accumulated muscle waste products. The macrophages secrete cytokines, which are messenger chemicals that signal the release of various growth factors. Cytokines also promote the entry of other immune cells into the area of muscle fiber damage, including lymphocytes, neutrophils and monocytes.
    The cytokines involved in muscle repair include interleukin-1, interleukin-6 and tumor necrosis factor. Other initial inflammatory substances that are vital for the process are prostaglandins, which are hormonelike chemicals made from dietary fat. In particular, prostaglandin F2a, derived from arachidonic acid, is pivotal in muscle protein synthesis. The importance of the initial inflammation is illustrated by recent studies showing that when you take an anti-inflammatory drug following training, muscle repair and muscle protein synthesis are inhibited. Fortunately, aging doesn’t seem to have any effect on the prostaglandin response to training.⁴

                                 The Muscle Growth Factors

     Various growth factors and hormones also are directly involved in the repair and anabolic processes within exercised muscle. Some are used in drug form for athletic and bodybuilding purposes.

                                        

                                          Insulinlike growth factor 1

    IGF-1 is produced both systemically and locally in muscle. It’s a string of amino acids in a specific sequence. Human growth hormone stimulates the production of IGF-1 in the liver, and IGF-1 activity is considered the source of most of the anabolic effects associated with growth hormone.
     In muscle, IGF-1 promotes the activity of satellite cells.⁵ It splits into two variants, the other being mechano growth factor. MGF is considered far more potent than localized IGF-1 in muscle.⁶ It replenishes the pool of muscle satellite cells, and a lack of MGF explains why older people cannot efficiently activate their satellite cells after exercise. Interestingly, when older men are given growth hormone and then lift weights, their bodies produce increased levels of MGF, leading to muscular gains. The growth hormone does that because it increases IGF-1, which then produces MGF.
     Studies of animals injected with MGF show gains of 25 percent in muscle fiber size after only three weeks. In contrast, using gene therapy to deliver IGF-1 genes directly into a muscle resulted in a 15 percent muscle size increase after four months.
     Research like that has two implications. The first is that gene therapy involving upgraded local production of IGF-1 or, preferably, MGF dramatically offsets the loss of muscle size and strength common with aging, so it may be of use in treating various neuromuscular disorders. The second is that MGF is a prime candidate for future athletic doping use. Already, rumors published on the Internet indicate that some athletes may be using MGF, although how and whether they actually got a still experimental drug is open to question.
Besides activating satellite cells, IGF-1 sets off so-called downstream growth pathways, such as the Akt, mTOR and P70 signaling pathways, all of which are involved in muscle protein synthesis.⁷ You may have read recent ads touting products that “turn on the genetic muscle machinery.” They’re based on the idea that oral intake of certain nutrients, such as branched-chain amino acids, can activate downstream growth pathways and overcome age deficits.⁸

                                              Hepatocyte growth factor

So named because its growth-promoting effects were originally observed in liver tissue, HGF is activated by muscle injury and is a potent stimulant to satellite cell activity. In one study HGF directly injected into the site of muscle injury led to a 300 percent increase in satellite cell activity.⁹
     Its release in injured muscle is instigated by nitric oxide, explaining one way in which NO promotes muscular growth. Inhibiting the release of NO also leads to a blockage of HGF release.

                                                

                                                 Fibroblast growth factor

FGF increases the proliferation of satellite cells following injury to muscle fibers. Although several FGFs exist, one in particular, FGF-6, is expressed specifically in muscle and is not upregulated during regeneration.¹¹

                                 The Hormonal Effect

Various anabolic hormones, including growth hormone, IGF-1, testosterone and insulin, all play vital roles in promoting muscular size and strength gains.

1) Growth hormone

As noted, most of the anabolic effects of GH are attributed to the stimulation of IGF-1 promoted by GH release. The IGF-1 produced in muscle splits into two variants, the more potent being MGF. IGF-1 is likely the most potent growth factor in relation to satellite cells, since it’s involved in all three processes of satellite cells: activation, proliferation and differentiation.
     Studies show that most of the gains attributed to GH use consist of water retention and connective tissue, with no effect on muscle contractile proteins. On the other hand, GH’s effects in maintaining the integrity and healing ability of connective tissue is beyond debate, which would mean that it’s still useful to athletes. In addition, combining weights with GH appears to increase the selective release of MGF, which is without question anabolic in muscle. MGF is potent enough to restore muscle gains in older people, indicating a use for GH until MGF gene therapy is perfected.
Another thing to consider is that GH appears to promote the use of bodyfat as an energy source while sparing muscle glycogen reserves. That associates it with a beneficial effect on body composition.

2) Testosterone

       Test and its synthetic versions (known as anabolic steroids) is the primary hormone associated with increased muscle size to most people. Some recent studies show that testosterone directly activates satellite cells, which explains a large part of its anabolic effect.¹² That makes sense, since satellite cells are known to produce androgen receptors, which interact with testosterone.¹³
In animals and humans, testosterone increases the number of satellite cells in muscle. It also interacts with growth hormone and IGF-1, triggering the release of local IGF-1 in muscle. In fact, testosterone appears to make muscle cells more responsive to the effects of IGF-1, which could explain why some athletes stack it with growth hormone and IGF-1.
     The importance of testosterone in gaining muscular size and strength is illustrated by a new study.¹⁴ Twenty-two young men, all of whom had some minor experience in weight training, were divided into groups. One group got a drug called goserelin (3.6 milligrams), and the other got a placebo. The drug inhibits gonadotropin-releasing hormone in the hypothalamus, which turns off the body’s testosterone production. The subjects got it subcutaneously, or under the skin, every four weeks for 12 weeks. Both groups engaged in strength training for eight weeks.
     The drug suppressed both total and free testosterone in the treated group to the extent that the subjects’ testosterone levels were 10 percent below normal. Those in the placebo group—who didn’t get the active drug—made significant gains. Those in the drug group made no gains whatsoever in muscular size and strength. Even worse: They showed an increase in fat mass.
    The lack of testosterone in the drug group led to a depression in IGF-1, which in turn led to decreased muscle repair due to satellite cell depression. Testosterone also offsets the effects of cortisol, a catabolic adrenal hormone produced during exercise. Having a metabolic profile that knocks out big T while leaving the effects of cortisol unchecked inevitably leads to no muscle gains coupled with increased bodyfat, especially in the trunk.
    Interestingly, two subjects in the drug group showed extreme increases in lean body mass, despite having low testosterone levels. The authors explain the apparent anomaly by noting that the adrenal glands produce 10 percent of androgen in men, and that would not be suppressed by the drug used in the study, which acts only on the pituitary gland to prevent the release of luteinizing hormone. IGF-1, MGF and other muscle growth factors may not have been affected in these particular young men, but they can be considered an exception to the rule, since the study clearly shows that a lack of sufficient testosterone does prevent muscle gains in most people.

                       The Anti-Growth Factors: Myostatin and Cortisol

Some substances that inhibit muscle growth also play a role in how fast you make gains. The most familiar of them is cortisol.
      Cortisol is considered a stress hormone, since any type of stress provides a stimulus for its release from the cortex portion of the adrenal glands. The release of cortisol is governed by a biochemical cascade. First, stress is perceived in the brain in the hypothalamus, which directly interacts with the nervous system. The hypothalamus then releases corticotropin-releasing hormone, which travels in the brain’s portal blood system to the pituitary gland. Upon arrival, CRF stimulates the synthesis and release of ACTH, which then travels in the blood to the adrenal glands, where it dictates the synthesis and release of cortisol.
    Cortisol has acquired an unsavory reputation as the body’s primary catabolic hormone. The constant stress of everyday life, including the stress of intense exercise, leads cortisol to have an overkill effect. If the level of cortisol exceeds that of its anabolic opposites GH and testosterone, a catabolic state results, leading to a loss of muscle.
      Excess cortisol promotes fat deposition in the trunk, though that is more often seen in pathologic excesses of cortisol, as occurs with Cushing’s disease. In normal instances, cortisol encourages the use of fat as an energy source, particularly after exercise.
     Cortisol is also a potent immunosuppressive and anti-inflammatory mediator—most apparent when certain drugs are used that suppress cortisol release. Athletes who resort to such drugs often report severe joint pain, the result of insufficient anti-inflammatory activity.
   The good news is that it’s not hard to control cortisol release through nutrition. Just taking in carbs during and after training significantly curtails its catabolic effects. Using a supplement rich in branched-chain amino acids will blunt or prevent them, as will the amino acid glutamine. A recently published study showed that glutamine specifically blocked cortisol’s catabolic effects in muscle by preventing a cortisol-promoted increase in myostatin.¹⁵
      Myostatin is a protein made up of 375 amino acids.¹⁶ It was initially identified by a group at the Johns Hopkins Medical center in Baltimore in 1997. Researchers noticed that mice who lacked the genes to produce myostatin were 30 percent heavier than normal mice, and the extra weight consisted entirely of muscle. That effect was also observed in double-muscled cattle, with the animals having mutations in the myostatin gene that caused them to have huge, defined muscle. In 2004 a report emerged of a human baby born without myostatin genes who was also noticeably stronger and more muscular than other children.
Myostatin does its dirty work in muscles—against IGF-1 and other muscle growth factors—by inhibiting the proliferation and differentiation of satellite cells. Several top pro bodybuilders are said to have mutant genes that make them produce less myostatin than normal. Such people would be far more responsive to training, even without anabolic steroids and other drugs.
    Myostatin and cortisol appear to interact, in that they increase each other’s levels. Diseases entailing catabolic states, such as certain forms of cancer and HIV, are characterized by higher levels of both hormones.
      Most but not all studies show that weight training lowers myostatin.^{17, 18, 19} One experiment also showed that the effect was accentuated by the use of a high-quality protein supplement. Excess aerobic exercise (more than 60 minutes in one session) will increase both cortisol and myostatin.
     A few years ago some supplement companies attempted to sell a pricey myostatin blocker derived from a type of seaweed. While it did block myostatin in the test tube, further trials showed it to be ineffective in the human body. Subsequently, the researchers who discovered myostatin announced the production of a drug that was effective in the body, promoting a 60 percent increase in animal muscle growth. Another company, Wyeth Pharmacueticals, already has an artificial antibody drug (MYO-029) that blocks myostatin in the human body, intended for the treatment of muscular dystrophy. No doubt the drugs will eventually trickle down into athletic use, and the results should be interesting.
     The factors affecting muscle growth and strength gains are complex and not yet fully understood. What is known and accepted, however, is that the long-held rules of bodybuilding—proper nutrition, rest and judicious levels of exercise—will do the most to trigger the internal events that build muscle.

References
¹ Kadi, F., et al. (2005). The behavior of satellite cells in response to exercise: what have we learned from the human studies? Eur J Physiol. 451:319-27.
² Kadi, F., et al. (1999). Effects of anabolic steroids on the muscle cells of strength-trained athletes.Med Sci Sports Exerc. 31:1528-34.
³ Charifi, N., et al. (2003). Effects of endurance training on satellite cell frequency in skeletal muscle of old men. Muscle Nerve. 28:87-92.
⁴ Trappe, T., et al. (2006). Effects of age and resistance exercise on skeletal muscle interstitial prostaglandin F2a. Prostag Leukot Ess Fatty Acids. 74:175-81.
⁵ Charge, S., et al. (2004). Cellular and molecular regulation of muscle regeneration. Physiol Rev. 84:209-238.
⁶ Goldspink, G. (2005). Research on mechano growth factor: Its potential for optimising physical training as well as misuse in doping. Br Sports Med. 39:787-88.
⁷ Guttridge, D.C. (2004). Signaling pathways weigh in on decisions to make or break skeletal muscle. Curr Opin Clin Nutr Metab Care. 7:443-50.
⁸ Proud, C.G. (2002). Regulation of mammalian translation factors by nutrients. Eur J Biochem. 269:5338-5349.
⁹ Allen, R.E., et al. (1995). Hepatocyte growth factor activates quiescent skeletal muscle satellite cells in vitro. J Cell Physiol. 165:307-12.
¹⁰ Anderson, J.E. (2000). A role for nitric oxide in muscle repair: Nitric oxide-mediated activation of muscle satellite cells. Mol Biol Cell. 11:1859-74.
¹¹ Scime, A., et al. (2006). Anabolic potential and regulation of the skeletal muscle satellite cell populations. Curr Opin Clin Nutr Metabolic Care. 9:214-219.
¹² Sinha-Hikim, I., et al. (2003). Testosterone-induced muscle hypertrophy is associated with an increase in satellite cell number in healthy, young men. Am J Physiol Endocrinol Metab. 285:E197-E205.
¹³ Chen, Y., et al. (2005). Androgen regulation of satellite cell function. J Endocrin. 186:21-31.
¹⁴ Kvorning, T., et al. (2006). Suppression of endogenous testosterone production attenuates the response to strength training: A randomized, placebo-controlled and blinded intervention study. Am J Physiol Endocrin Metab. 291:E325-E332.
¹⁵ Salchian, B., et al. (2006). The effect of glutamine on prevention of glucocorticoid-induced skeletal muscle atrophy is associated with myostatin suppression. Metabolism. 55:1239-47.
¹⁶ Gonzalez-Cadavid, N.F., et al. (2004). Role of myostatin in metabolism. Curr Opin Nutr Metab Care. 7:451-457.
¹⁷ Roth, S.M., et al. (2003). Myostatin gene expression is reduced in humans with heavy resistance strength training: a brief communication. Ex Biol. 228:706-09.
¹⁸ Walker, K.S., et al. (2004). Resistance training alters plasma myostatin but not IGF-1 in healthy men. Med Sci Sports Exerc. 36:787-93.
¹⁹ Willoughby, D.S. (2004). Effects of heavy resistance training on myostatin mRNA and protein expression. Med Sci Sports Exerc. 36:574-82.  

   

©,2015 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited

Have you been ripped off  by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Jerry Brainum's book Natural Anabolics, available at JerryBrainum.com.

 

The Applied Ergogenics blog is a collection of articles written and published by Jerry Brainum over the past 20 years. These articles have appeared in Muscle and Fitness, Ironman, and other magazines. Many of the posts on the blog are original articles, having appeared here for the first time. For Jerry’s most recent articles, which are far more in depth than anything that appears on this blog site, please subscribe to his Applied Metabolics Newsletter, at www.appliedmetabolics.com. This newsletter, which is more correctly referred to as a monthly e-book, since its average length is 35 to 40 pages, contains the latest findings about nutrition, exercise science, fat-loss, anti-aging, ergogenic aids, food supplements, and other topics. For 33 cents a day you get the benefit of Jerry’s 53 years of writing and intense study of all matters pertaining to fitness,health, bodybuilding, and disease prevention.

 

See Jerry's book at  http://www.jerrybrainum.com

 

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Muscle Fiber Fact vs. Fiction by Jerry Brainum

New Findings Reveal the Truth Behind Muscle Growth

It’s no secret that having favorable genetics gives you a significant head start on bodybuilding success. Muscle fibers can be among those genetic advantages. Longer muscles, which have more muscle fibers, can produce greater rates of muscular growth. The number of fibers is determined at birth, although the types of fibers may be subject to change to a certain extent. Take, for example, the calf muscles. Having high calves usually means you have fewer muscle fibers in your calves, which translates into less potential for growth. That doesn’t preclude muscle growth; it just means that the odds of obtaining massive calves are stacked against you.
      Human muscle fibers come in three main types:
1) Type 1, or slow-twitch, are smaller and generally more suited to endurance, or aerobic, activity.
2) Type 2A are intermediate, showing some of the characteristics of types 1 and 2B fibers.
3) Type 2B are most the amenable to growth. They’re the “strength and size” fibers. They have a low resistance to fatigue, as they lack the extensive blood vessels and mitochondria present in type 1 fibers. They work mainly through anaerobic metabolism. On the other hand, type 2B fibers have the thickest motor neuron connections, which means they produce greater force than the other kinds of fibers.
Muscle fibers are recruited in a certain order, with type 1 fibers being activated first, followed in order by the type 2As and 2Bs. Most exercise physiology textbooks say that type 2B fibers can be recruited only by heavy weight and high intensity. For years bodybuilders have been told that they need heavy weights and high intensity to achieve gains in muscle size and strength. That’s because they need to activate type 2B muscle fibers.
      Years ago a study was published that compared the muscle fibers in elite competitive bodybuilders to those of unathletic physical education students. Because the bodybuilders had arm circumferences that averaged 19 to 20 inches, the researchers fully expected the bodybuilders to show far larger muscle fibers than the students. After all, muscle growth involves a thickening of muscle fibers as a result of intense exercise, which causes increased muscle protein synthesis. Yet when viewed under the microscope, the muscle fibers of the massive bodybuilders weren’t all that different from those of the far less muscular students. How could that be?
       The researchers suggested that years of heavy and intense training had encouraged a process called hyperplasia, which is a splitting of muscle fibers. So while the bodybuilders’ individual muscle fibers weren’t larger than normal, they’d produced far more of them. As the fibers themselves weren’t counted, the hyperplasia hypothesis remained speculative, but how else to explain the notable disparity in muscle size between the bodybuilders and the students?
      A more recent study also produced a number of surprises. Once again, champion bodybuilders were compared to ordinary college students. The bodybuilders all consumed a high-protein diet, averaging 200 to 220 grams daily, and none had used anabolic steroids for two years prior to the study—or so they said. They trained regularly four to six times a week, for three to four hours at each session. The muscles examined in the study were the front thighs, and the bodybuilders’ leg routines averaged two sessions a week. They did 12 sets of 10 to 20 reps, using 70 to 90 percent of one-rep-maximum weights.
Note that the study examined single muscle fibers. Since the type 2B fibers are the muscle fibers most likely to grow, it stands to reason that the bodybuilders in the study would have an abundance of such fibers, or at least more of them than the other kinds of muscle fibers. The reality was that they showed a higher portion of types 1 and 2A fibers, with a near complete absence of type 2Bs. How could that be?
       Training. Typical bodybuilding training isn’t characterized by using maximum weight for six reps or fewer but instead involves higher reps, less rest time between sets and high training intensity. It turns out that this style of training favors the transformation of fibers into type 2As, which have some of the characteristics of both strength and endurance, exactly matching the way most bodybuilders train. The body adapts by spurring the development of the muscle fibers most efficient for the purpose: type 2A fibers.
      While type 2Bs have low fatigue resistance, 2As have intermediate fatigue resistance. Type 2B fibers last less than a minute before fatigue sets in, while 2As can go for five minutes. One reason is that 2A fibers contain more mitochondria—the cell’s energy factory—than type 2Bs and are more efficient at using oxygen, thus making fuel more available.
     As for type 2Bs, the authors say that in bodybuilders they work more or less as reserve fibers. When recruited during exercise, they convert into the type 2A fibers that are so abundant in bodybuilders. Interestingly, high numbers of type 2B fibers are found in obese women and in those with spinal cord injuries, in the latter case likely as the body’s way of compensating for the injury.
     One limitation of the study, the authors suggest, is that the bodybuilders might have been born with greater numbers of type 2 muscle fibers, thus having a genetic predisposition toward more muscle growth.
What does it all mean in a practical sense? More than anything that bodybuilders’ knowledge is empirical. They’ve discovered from years of experience that using weights that give them a range of eight to 12 reps yields the most muscle growth. Now we know why: Because of the middle-of-the-road type 2A fibers, which have characteristics of both aerobic and anaerobic muscle fibers. So for maximum training progress it’s best to gear your training for the type 2As. That doesn’t mean it’s useless to use heavy weights that give you six reps or fewer per set. They’re great for strengthening connective tissue and for activating the type 2B fibers that will transform into 2A fibers with continued training.

Kesiidis, N., et al. (2008). Myosin heavy chain isoform distribution in single fibers of bodybuilders. Eur J Appl Physiol. 103(5):579-83.

  
©,2015 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited

Have you been ripped off  by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Jerry Brainum's book Natural Anabolics, available at JerryBrainum.com.

 

The Applied Ergogenics blog is a collection of articles written and published by Jerry Brainum over the past 20 years. These articles have appeared in Muscle and Fitness, Ironman, and other magazines. Many of the posts on the blog are original articles, having appeared here for the first time. For Jerry’s most recent articles, which are far more in depth than anything that appears on this blog site, please subscribe to his Applied Metabolics Newsletter, at www.appliedmetabolics.com. This newsletter, which is more correctly referred to as a monthly e-book, since its average length is 35 to 40 pages, contains the latest findings about nutrition, exercise science, fat-loss, anti-aging, ergogenic aids, food supplements, and other topics. For 33 cents a day you get the benefit of Jerry’s 53 years of writing and intense study of all matters pertaining to fitness,health, bodybuilding, and disease prevention.

 

See Jerry's book at  http://www.jerrybrainum.com

 

Want more evidence-based information on exercise science, nutrition and food supplements, ergogenic aids, and anti-aging research? Check out Applied Metabolics Newsletter at www.appliedmetabolics.com

 

Arnold's rules for success by Jerry Brainum

It would be hard to argue that Arnold Schwarzenegger has had a very successful life thus far.Yes, he's had a few bumps in the road, such as the disclosure that he had a child out of wedlock.But as he has done with most other problems in his life, Arnold appears to have accepted this "mistake," as he puts it, and moved on. In his recently published autobiography, Total Recall, Arnold recounts his life in exhaustive detail. Perhaps the most interesting part of the book, however, is the chapter called "Arnold's Rules." This chapter is a synopsis of how Arnold became successful. What are these rules, and are they applicable to all of us? The rules are as follows:

1) Turn your liabilities into assets-Arnold mentions how he used what would normally be barriers to success in the film world, namely his size and accent, and instead turned them in unique traits that aided his climb to the top in the film business.
2) When someone tells you no, you should hear yes-I can testify that this is the very essence of Arnold's success. No matter what the odds were against him, Arnold turned a deaf ear. He was like the real-life version of the Terminator: an unstoppable force that would not rest until it got what it wanted.
3) Never follow the crowd, go where it's empty-By this he means, become a non-conformist. Don't do what everyone else does. Do what you want to do (within reason).
4) No matter what you do in life, selling is part of it-We are always selling ourselves, one way or the other. When we meet a prospective romantic partner, we are in a definite sales mode. Arnold's philosophy is that we have to sell ourselves to succeed, and cannot passively wait for success to come to us.
5) Never let pride get in your way-the anecdote that Arnold relates in the book for this doesn't make sense. So I guess in that respect, he didn't let pride get in his way!
6) Don't overthink-Arnold thinks that many people with extensive knowledge overanalyze things, and thus talk themselves out of possibly lucrative opportunities.He suggests that if something appears promising, it's better to just forge ahead and not think too deeply about it. Such a plan can either prove very successful, or lead to utter disaster.
7) Forget Plan B-This is similar to the previous rule. Just do it, and don't worry about it. Don't even think about alternative ideas. Again, this is either sage advice, or a recipe for disaster. In actuality, Arnold often consulted with knowledgeable people in fields that he was interested in before proceeding.
8) You can use outrageous humor to settle a score- One wonders if he has tried this yet with his wife.
9) The day has 24 hours- Arnold says that you should not waste your time on unproductive activity. He then goes on the mention how he trained 5 hours a day, attended school, worked at construction, all of which would have precluded getting any sleep.
10) Reps, reps, reps- Arnold confirms the notion that becoming a master at any task requires constant practice. The usual statement in this regard is that it takes 10,000 hours of practice to become a master at anything.
11) Don't blame your parents- Arnold discusses in the book the stern discipline that was imparted on him by his father. He considers that an asset, since he turned it into a lifelong drive to succeed.
12) Change takes big balls-True success requires a large element of risk.
13) Take care of your body and your mind.
14)  Stay hungry-When you've achieved success in one endeavor, move on to another. Never be satisfied, but always seek even more success in several fields.

I would add one more rule:

15) Never fool around with the hired help.

©,2012 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited

Have you been ripped off  by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Jerry Brainum's book Natural Anabolics, available at JerryBrainum.com.

 

The Applied Ergogenics blog is a collection of articles written and published by Jerry Brainum over the past 20 years. These articles have appeared in Muscle and Fitness, Ironman, and other magazines. Many of the posts on the blog are original articles, having appeared here for the first time. For Jerry’s most recent articles, which are far more in depth than anything that appears on this blog site, please subscribe to his Applied Metabolics Newsletter, at www.appliedmetabolics.com. This newsletter, which is more correctly referred to as a monthly e-book, since its average length is 35 to 40 pages, contains the latest findings about nutrition, exercise science, fat-loss, anti-aging, ergogenic aids, food supplements, and other topics. For 33 cents a day you get the benefit of Jerry’s 53 years of writing and intense study of all matters pertaining to fitness,health, bodybuilding, and disease prevention.

 

See Jerry's book at  http://www.jerrybrainum.com

 

Want more evidence-based information on exercise science, nutrition and food supplements, ergogenic aids, and anti-aging research? Check out Applied Metabolics Newsletter at www.appliedmetabolics.com

 

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Creatine Myths Exploded by Jerry Brainum

There’s an old saying that when you’re at the top, someone’s always trying to bring you down. The adage certainly applies to creatine. Since its commercial introduction in 1993, creatine has become one of the most popular bodybuilding supplements, and for good reason. Countless studies prove its effectiveness, the scientific consensus being that it works for 80 percent of its users. The other 20 percent usually eat red meat habitually. Red meat contains high levels of natural creatine, and those who eat it regularly tend to have more creatine stored in their muscles. That’s why they don’t respond as dramatically to the supplement as vegetarians or those who eschew eating meat.
       Along with its commercial success, however, creatine has also been subject to much unfounded criticism. The misinformation is fueled by poorly researched popular media reports about its effects. Indeed, some newspaper and television news features have identified creatine as a steroid. In fact, it’s an amino acid by-product synthesized in the liver, kidney and pancreas from three amino acid precursors: methionine, glycine and arginine. The body produces about one gram of creatine a day, and if you eat meat, you get another gram or two as well. Labeling creatine a drug of any kind is an example of shoddy research.
      Popular media, though, aren’t the sole purveyors of creatine misinformation. Science journals regularly publish alarming reports suggesting a dark future for creatine users. A closer perusal of them usually shows how irrelevant they are for those in good health. It’s like those reports that eating lots of protein is risky for those with kidney failure. There’s zero evidence that either creatine or a high-protein intake is hazardous for people who have normal kidney function.
      Among the side effects attributed to creatine are excess kidney stress, muscular cramps and dehydration. Two recently published studies, however, definitively prove that the claims are false.
The theory is that creatine use promotes a shift of water from extracellular and into intracellular compartments. Critics say that that makes it hard to maintain cooler body temperature and alters electrolyte, or mineral, balance, leading to muscle cramps. Studies that have found muscle cramps and overheating with creatine use have by and large involved athletes training in hot weather, when they may not have been drinking enough water to balance sweating and other fluid loss from the heat and exertion. Other studies show the opposite: Creatine appears to offer significant protection against heat illness, dehydration and muscle cramps. That makes sense because creatine increases total body water, which would protect against dehydration while lowering core body temperature.
      Then there’s the fear that creatine affects kidney function. The primary waste product of creatine metabolism, creatinine, is excreted through the kidneys, and with compromised kidney function, excess creatinine could produce kidney stress. In fact, a primary test of kidney function is called the creatinine-clearance test; in it excess creatinine points to problems with the filtering mechanism in the kidneys. Just because a clinical test uses a particular substance as a marker of bad kidney function, however, doesn’t prove the substance caused the problem.
      One study, which reviewed the literature about the effects of creatine in relation to muscle cramps and dehydration, cited a 1998 case study published in the Lancet describing a 25-year-old man who experienced a decline in kidney function after taking 20 grams of creatine a day. Complicating the report was the fact that the man had kidney disease. When he stopped using the creatine, his symptoms abated, leading the authors to suggest that creatine was toxic to kidney function. A French newspaper reported that three days after the review was published, but it totally overlooked the fact that the man already had serious kidney disease. In any case, taking 20 grams of creatine after you’ve done a typical creatine-loading phase of five days is just plain foolish, as nearly all of the creatine is rapidly excreted once the muscles are loaded.
     Besides questionable human studies pointing to creatine-induced renal stress, a number of animal studies have been used to bolster that criticism, but those, too, are red herrings, since creatine isn’t a normal nutrient for many animal species and may not even be absorbed. For example, creatine intake causes chronic hepatitis in mice but not in rats. In contrast, humans easily and rapidly absorb it, even though many ads attempt to deny that so they can sell “superior” creatine supplements.
     Complicating the picture is the fact that the creatinine test, the primary test for kidney function, isn’t accurate for those who use creatine, particularly during a loading phase. A recent study compared men, ages 18 to 35, who got either 10 grams of creatine or a placebo daily for three months. The researchers used a newer test of kidney function that measured a serum protein called cystatin C. Cystatin C is regularly filtered in the kidneys and easily reabsorbed, since it has a low molecular weight. A loss of cystatin C is a good indicator of a defect in the glomerular filtration system of the kidneys and isn’t affected by creatine metabolism.
      The study found that, based on monitoring cystatin C excretion, taking in 10 grams of creatine daily for three months had no adverse effects on kidney function. The subjects also participated in aerobic exercise for 40 minutes three times a week. Tests on those in the placebo group showed that the exercise alone improved kidney function. That was attributed to the health-promoting effects of exercise, such as more efficient glucose control, lower blood pressure and a reduction in oxidative stress and bodyfat levels. Significantly, those are the same factors that offer lifelong kidney protection, suggesting that regular exercise is one of the best things you can do to preserve kidney function.

References

Dalbo, V.J., et al. (2008). Putting the myth of creatine supplementation leading to muscle cramps and dehydration to rest. Brit J Sports Med. 2008;42:567-73.


©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited. 

Have you been ripped off by supplement makers whose products don’t work as advertised? Want to know the truth about them? Check out Jerry Brainum's book Natural Anabolics, available at JerryBrainum.com

 
 

The Applied Ergogenics blog is a collection of articles written and published by Jerry Brainum over the past 20 years. These articles have appeared in Muscle and Fitness, Ironman, and other magazines. Many of the posts on the blog are original articles, having appeared here for the first time. For Jerry’s most recent articles, which are far more in depth than anything that appears on this blog site, please subscribe to his Applied Metabolics Newsletter, at www.appliedmetabolics.com. This newsletter, which is more correctly referred to as a monthly e-book, since its average length is 35 to 40 pages, contains the latest findings about nutrition, exercise science, fat-loss, anti-aging, ergogenic aids, food supplements, and other topics. For 33 cents a day you get the benefit of Jerry’s 53 years of writing and intense study of all matters pertaining to fitness,health, bodybuilding, and disease prevention.

 

See Jerry's book at  http://www.jerrybrainum.com

 

Want more evidence-based information on exercise science, nutrition and food supplements, ergogenic aids, and anti-aging research? Check out Applied Metabolics Newsletter at www.appliedmetabolics.com