Bodybuilding Endocrinology Part III: Maximizing Anabolic Drive
Bulletin No. 17, Bodybuilding Endocrinology Part III: Maximizing Anabolic Drive
Parrillo Performance Products
(800) 344-3404
In the previous bulletins we’ve been discussing nutrient partitioning and dietary strategies to channel nutrients to the lean compartment and not to fat stores. We saw that muscle gain and fat loss are controlled largely by hormones - chemical signals sent out by the endocrine glands which direct the body’s metabolism. We discussed the insulin-glucagon axis in detail and saw that it has a major influence in determining the set point in the hypothalamus - the weight regulating center of the body that decides how much fat we will carry (1,2). Insulin is the body’s most powerful anabolic hormone, acting to transport glucose and amino acids into cells. This supplies energy and the building blocks for growth. Insulin is required for muscular growth, and indeed for life.
Glucagon has the opposite actions of insulin. It moves glucose and amino acids out of cells and into the bloodstream when blood sugar gets too low. These two pancreatic hormones work in balance to provide a 
relatively uniform blood glucose level, to ensure that the brain doesn’t run out of fuel. The good news is that insulin and glucagon levels are determined solely by diet, so we can exert great control over these hormones by our eating habits. The Parrillo Performance Nutrition Program was designed to take advantage of this fact to keep insulin and glucagon at just the right levels to build muscle and burn fat. Last month we talked about how to use Pro-Carb FormulaTM and Hi-Protein PowderTM to fine-tune these hormone levels to optimize your body’s metabolism. The bad news, however, is that insulin is a powerful stimulus for fat growth as well as muscle growth (3,4). It stores fat inside fat cells as well as it stores protein inside muscle cells. This is why on the Parrillo Program meals are structured so as to release carbs into the bloodstream slowly. This results in a lower and more uniform insulin level, which helps minimize any fat storage.
This is also why you should stay away from any products high in simple carbohydrates. These products elicit a rapid, large insulin release. Any time you empty a lot of carbohydrate calories into your bloodstream very rapidly and have a high insulin level you will store those calories as fat. High sugar products would be better called “fat optimizers.” The body can only build muscle so fast, but it has an unlimited ability to store fat. Muscle building is a slow and difficult process, and it works better when you supply your body with slow and steady supply of energy and nutrients. This also provides a more uniform energy level instead of the periods of hypoglycemia you experience after eating simple sugars. The bad news about glucagon is that, although it stimulates fat breakdown (lipolysis), its actions are mostly limited to the liver (3,4). Like insulin, glucagon is released from the pancreas and transported directly to the liver by the portal vein. While enough insulin is released to effect the whole body, glucagon is released in smaller amounts and most of it stays in the liver. Therefore, glucagon is not a very potent stimulator of lipolysis in peripheral tissues, such as body fat stores. But don’t get discouraged, the insulin-glucagon axis is still one of the most important controllers of nutrient partitioning - it’s just not the whole story.
This month we’ll begin our discussion of three other hormones that complete the puzzle: growth hormone, testosterone and epinephrine. Once you learn how to control these hormones and add them to your arsenal you’re likely to see the best gains in your life, and get more ripped than you though possible. Now we’re pulling out the big guns! Epinephrine, more commonly known to the layman as adrenaline, is the body’s most powerful stimulus for fat breakdown (3,4). It is produced by the adrenal glands, two small glands located one just above each kidney. Actually, epinephrine serves not only as a hormone by also acts as a neurotransmitter in the nervous system. This underscores the relationship of the nervous system and the endocrine system working together as a control and communication network to provide instructions to the body. Nerve impulses are conducted to the center of the adrenal gland, the adrenal medulla, by the sympathetic division of the nervous system. This triggers epinephrine to be released into the bloodstream. Epinephrine has many effects. One you’ve probably noticed is the “fight or flight” response that occurs when you’re really scared or suddenly startled. When your skin and lips turn pale, you feel cold and clammy, you start sweating and your heart pumps really hard and fast - that’s epinephrine.
It’s a reaction animals have when they’re confronted by an enemy and have to either fight or run away. It’s the feeling of being “scared to death” that most of us have experienced at one time or another. It’s the “adrenaline rush” you get from bungee jumping. This surge of epinephrine is mediated by a large sympathetic discharge in 
the adrenal medulla. This gland has a large blood supply for its size and the epinephrine is rapidly carried throughout the body. It primes your muscles for action and mobilizes fat from adipose stores to provide energy. It increases your heart rate, blood pressure and the force of your heart’s contractions. Under normal conditions, epinephrine is delivered to fat cells mostly by direct innervation of the fat cells by the sympathetic nervous system, rather than systematic release to the whole body from the adrenal medulla. Its release is increased during exercise, and this is the primary mechanism whereby exercise serves as a stimulus for fat loss. Epinephrine binds to receptors on fat cells and generates a metabolite called cyclic AMP, or cAMP. cAMP activates an enzyme called protein kinase, which in turn activates another enzyme called hormone sensitive lipase. Hormone sensitive lipase breaks down triglycerides (the molecular form in which body fat is stored) into free fatty acids (FFAs) and glycerol.
The FFAs then leave the fat cell and are carried by the blood to the muscles, where they are burned for energy (3,4). This is how exercise works to help you lose fat. While insulin and glucagon are controlled entirely by diet, the most effective way to control growth hormone, testosterone and epinephrine is by exercise (5,6). This is why exercise is required to gain muscle and lose fat. If you try to lose weight by cutting calories, about half of the weight you will lose will be muscle. Conversely, if you gain weight simply by increasing calories (without exercising) you’ll just get fat. Exercise is required to set up the proper hormonal milieu allowing selective fat loss and muscle gain. The favorable effects of exercise in increasing muscle mass while decreasing fat stores are mediated largely through growth hormone, testosterone and epinephrine. Therefore, to really fine tune nutrient partitioning to sculpt the ultimate physique, we have to talk about effective training strategies to optimize these hormones. Growth hormone (GH) is the most important hormone responsible for normal growth during childhood. Without growth hormone, a person will never attain adult stature. Growth hormone has profound effects on the growth of the skeleton as well as the muscles.
Testosterone and estrogen produced during puberty cause the skeleton to mature and stop growing, but growth hormone still promotes muscle growth and fat loss in adults. Growth hormone is released from the 
pituitary gland when it receives the appropriate signals. One of these signals is “growth hormone releasing hormone” (GHRH) which comes from the hypothalamus. There are several things you can do to naturally increase your GH levels. One is to get a good night’s sleep. Growth hormone is released maximally during sleep, normally about three hours after you fall asleep. Trying to build muscle without getting enough rest is nearly impossible. Second, GH release is increased during and just after intense exercise (5,6). The most effective training style for increasing GH release is high volume training (5,6,7). We recommend a mixture of low rep, medium rep and high rep work to maximally stimulate all the muscle fibers as well as train the nervous system. This results in optimal increases in size and strength.
The ultimate training program for bodybuilders is described in the Parrillo Performance Training Manual and High Performance Bodybuilding book. Third, eat a high protein diet. This not only stimulates GH release, but also provides the building blocks you need to build new muscle tissue. Fourth, certain combinations of amino acids have been shown to increase GH release and result in increased lean body mass (7). Enhanced GH FormulaTM contains the most effective combination ever developed. Take it on an empty stomach (this is important) just before training and before bed. In the following bulletins we’ll continue our discussion of muscle-building and fat-burning hormones and talk more about growth hormone and testosterone. The most exciting part of the story is yet to come! Of course, merely having a detailed intellectual understanding of how nutrition and exercise come together in your body to build muscle and burn fat does nothing to achieve those results. It’s up to you to put this information to use in the gym and at the dinner table. Don’t forget the basics of the Parrillo Philosophy: dedication, consistency and hard work. So train hard, eat right and do your aerobics. And have a great summer!
Parrillo Performance Products
(800) 344-3404
References
1. de Castro JM, Paullin SK, and DeLugas GM. Insulin and glucagon as determinants of body weight set point and microregulation in rats. J. Comp. Physiol. Psychol. 92: 571-579, 1978.
2. Remington DW, Fisher AG, and Parent EA. How to Lower your Fat Thermostat. Vitality House International, Provo, 1983.
3. Guyton, AC. Textbook of Medical Physiology. W.B. Saunders, 1991.
4. Johnson LR. Essential Medical Physiology. Raven Press, New York, 1992.
5. Kraemer WJ. Influence of the endocrine system on resistance training adaptations. Natl. Strength and Conditioning J. 14: 47-54, 1992.
6. Kraemer RR. Kilgore JL, Kraemer GR, and Castracane VD. Growth hormone, IGF-1, and testosterone responses to resistive exercise. Med. Sci. Sports Exerc. 24: 1346-1352, 1992.
7. Crist DM. Growth Hormone Synergism. DMC Health Sciences, Albuquerque, 1991.
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