For Those Bodybuilder and Sports Men

Muscle hypertrophy

Hypertrophy stimuli

A range of stimuli can increase the volume of muscle cells. Summarizing, these changes occur as an adaptive response that serves to increase the ability to generate force or resist fatigue in anaerobic conditions.

Strength training

Strength training typically produces a combination of the two different types of hypertrophy: contraction against 80 to 90% of the one repetition maximum for 2–6 repetitions (reps) causes myofibrillated hypertrophy to dominate (as in powerlifters, olympic lifters and strength athletes), while several repetitions (generally 8 – 12 for bodybuilding or 12 or more for muscular endurance) against a sub-maximal load facilitates mainly sarcoplasmic hypertrophy (professional bodybuilders and endurance athletes).[citation needed] The first measurable effect is an increase in the neural drive stimulating muscle contraction. Within just a few days, an untrained individual can achieve measurable strength gains resulting from "learning" to use the muscle. As the muscle continues to receive increased demands, the synthetic machinery is upregulated. Although all the steps are not yet clear, this upregulation appears to begin with the ubiquitous second messenger system (including phospholipases, protein kinase C, tyrosine kinase, and others). These, in turn, activate the family of immediate-early genes, including c-fos, c-jun and myc. These genes appear to dictate the contractile protein gene response.

Progressive overload is considered the most important principle behind hypertrophy, so increasing the weight, repetitions (reps), and sets will all have a positive impact on growth. Some experts create complicated plans that manipulate weight, reps, and sets, increasing one while decreasing the others to keep the schedule varied and less repetitive. It is generally believed that if more than 15 repetitions per set is possible, the weight is too light to stimulate maximal growth.

Anaerobic training

Experts and professionals differ widely on the best approaches to specifically achieve muscle growth (as opposed to focusing on gaining strength, power, or endurance); it was generally considered that consistent anaerobic strength training will produce hypertrophy over the long term, in addition to its effects on muscular strength and endurance. As testosterone is one of the body's major growth hormones, on average, men find hypertrophy much easier to achieve than women. Taking additional testosterone, as in anabolic steroids, will increase results. It is also considered a performance-enhancing drug, the use of which can cause competitors to be suspended or banned from competitions. In addition, testosterone is also a medically regulated substance in most countries, making it illegal to possess it without a medical prescription.

Factors affecting hypertrophy

Several biological factors such as age and nutrition can affect muscle hypertrophy. During puberty in males, hypertrophy occurs at an increased rate. Natural hypertrophy normally stops at full growth in the late teens. Muscular hypertrophy can be increased through strength training and other short duration, high intensity anaerobic exercises. Lower intensity, longer duration aerobic exercise generally does not result in very effective tissue hypertrophy; instead, endurance athletes enhance storage of fats and carbohydrates within the muscles, as well as neovascularization. An adequate supply of amino acids is essential to produce muscle hypertrophy.

Changes in Protein synthesis and muscle cell biology associated with stimuli

Protein synthesis

Ultimately the message filters down to alter the pattern of protein expression. The additional contractile proteins appear to be incorporated into existing myofibrils (the chains of sarcomeres within a muscle cell). There appears to be some limit to how large a myofibril can become: at some point, they split. These events appear to occur within each muscle fiber. That is, hypertrophy results primarily from the growth of each muscle cell, rather than an increase in the number of cells. Skeletal muscle cells are however unique in the body in that they can contain multiple nuclei, and the number of nuclei can increase.

Cortisol decreases amino acid uptake by muscle tissue, and inhibits protein synthesis.[6] The short-term increase in protein synthesis that occurs subsequent to resistance training returns to normal after approximately 28 hours in adequately fed male youths.

A small study performed on young and elderly found that ingestion of 340 grams of lean beef (90 g protein) did not increase muscle protein synthesis any more than ingestion of 113 grams of lean beef (30 g protein). In both groups, muscle protein synthesis increased by 50%. The study concluded that more than 30 g protein in a single meal did not further enhance the stimulation of muscle protein synthesis in young and elderly. However, this study didn't check protein synthesis in relation to training; therefore conclusions from this research are controversial.

It is not uncommon for bodybuilders to advise a protein intake as high as 2–4 g per kilogram of bodyweight per day. However, scientific literature such as 'Evaluation of protein requirements for trained strength athletes (November 1992)' has suggested this is higher than necessary, as protein intakes greater than 1.8 g per kilogram of body weight showed to have no greater effect on muscle hypertrophy. A study carried out by American College of Sports Medicine (2002) put the recommended daily protein intake for athletes at 1.2–1.8 g per kilogram of body weight. Conversely, Di Pasquale (2008), citing recent studies, recommends a minimum protein intake of 2.2 g/kg "for anyone involved in competitive or intense recreational sports who wants to maximize lean body mass but does not wish to gain weight. However athletes involved in strength events may need even more to maximize body composition and athletic performance. In those attempting to minimize body fat and thus maximize body composition, for example in sports with weight classes and in bodybuilding, it’s possible that protein may well make up over 50% of their daily caloric intake.

Microtrauma

Microtrauma, which is tiny damage to the fibers, may play a significant role in hypertrophy. When microtrauma occurs (from weight training or other strenuous activities), the body responds by overcompensating, replacing the damaged tissue and adding more, so that the risk of repeat damage is reduced. Damage to these fibers have been theorized as the possible cause for the symptoms of delayed onset muscle soreness (DOMS), and is why progressive overload is essential to continued improvement, as the body adapts and becomes more resistant to stress.

Myofibrillar vs. Sarcoplasmic hypertrophy controversy

In the bodybuilding and fitness community and even in some academic books skeletal muscle hypertrophy is described as being in one of two types: Sarcoplasmic or myofibrillar. According to this theory, during sarcoplasmic hypertrophy, the volume of sarcoplasmic fluid in the muscle cell increases with no accompanying increase in muscular strength, whereas during myofibrillar hypertrophy, actin and myosin contractile proteins increase in number and add to muscular strength as well as a small increase in the size of the muscle. Sarcoplasmic hypertrophy is characteristic of the muscles of certain bodybuilders while myofibrillar hypertrophy is characteristic of Olympic weightlifters. These two forms of adaptations rarely occur completely independently of one another, one can experience a large increase in fluid with a slight increase in proteins, a large increase in proteins with a small increase in fluid, or a relatively balanced combination of the two. In contrast to this theory it should be noted that when viewed in microscope, muscles are filled entirely by myofibrils, whether or not the muscles from bodybuilders or powerlifters are used. Also, very little actual evidence actually supports that the non-myofibrillar part of the sarcoplasm ever expands. Antagonists to this theory suggest that the cause of this popular notion is twofold: First, it is derived from fractioning of muscle used when measuring protein synthesis. This is a technique in which muscle proteins are separated biochemically into myofibrillar, sarcoplasmic, membrane and mitochondrial fractions for protein synthesis. This validity of this separation is poorly validated and also, the results of this fractionation and the usual following stable isotope protein synthesis measurement does not tell anything about the relative abundance of these protein fractions (as changes in protein synthesis are by definition relative (i.e. a change of 50% in a substance that constitutes 1% of the muscle is still insignificant in a physiological context). Secondly, the sarcoplasmic/ myofibrillar proponents use their theory to explain why bodybuilders have less relative strength than strength athletes. But this theory is not necessary to explain these differences. The physiological changes associated with training with very high volume and degrees of muscle fatigue produce difference neuromuscular adaptations that are different from those experienced by strength training with very high mechanical loads and less muscle fatigue.

In sports

Examples of increased muscle hypertrophy are seen in various professional sports, mainly strength related sports such as boxing, bodybuilding, mixed martial arts, rugby, professional wrestling and various forms of gymnastics. These athletes train extensively in strength as well as cardiovascular and muscular endurance training.

Anabolism

Anabolism (from Greek ana, "upward", and ballein, "to throw") is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy. One way of categorizing metabolic processes, whether at the cellular, organ or organism level is as 'anabolic' or as 'catabolic', which is the opposite. Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in respiration. Many anabolic processes are powered by adenosine triphosphate (ATP).

Anabolic processes tend toward "building up" organs and tissues. These processes produce growth and differentiation of cells and increase in body size, a process that involves synthesis of complex molecules. Examples of anabolic processes include the growth and mineralization of bone and increases in muscle mass. Endocrinologists have traditionally classified hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The classic anabolic hormones are the anabolic steroids, which stimulate protein synthesis and muscle growth. The balance between anabolism and catabolism is also regulated by circadian rhythms, with processes such as glucose metabolism fluctuating to match an animal's normal periods of activity throughout the day.

Myofibril

A myofibril is a basic unit of a muscle. Muscles are composed of tubular cells called myocytes or myofibers. Myofibers are composed of tubular myofibrils. Myofibrils are composed of long proteins such as actin, myosin, and titin, and other proteins that hold them together. These proteins are organized into thin filaments and thick filaments, which repeat along the length of the myofibril in sections called sarcomeres. Muscles contract by sliding the thin (actin) and thick (myosin) filaments along each other.

Actomyosin motors are important in muscle contraction (relying in this case on "classical myosins") as well as other processes like retraction of membrane blebs, filiopod retraction, and uropodium advancement (relying in this case on "nonclassical myosins").

The filaments of myofibrils, myofilaments, consist of two types, thick and thin.

Thin filaments consist primarily of the protein actin, coiled with nebulin filaments.

Thick filaments consist primarily of the protein myosin, held in place by titin filaments.

The protein complex composed of actin and myosin is sometimes referred to as "actomyosin."

In striated muscle, such as skeletal and cardiac muscle, the actin and myosin filaments each have a specific and constant length on the order of a few micrometers, far less than the length of the elongated muscle cell (a few millimeters in the case of human skeletal muscle cells). The filaments are organized into repeated subunits along the length of the myofibril. These subunits are called sarcomeres. The muscle cell is nearly filled with myofibrils running parallel to each other on the long axis of the cell. The sarcomeric subunits of one myofibril are in nearly perfect alignment with those of the myofibrils next to it. This alignment gives rise to certain optical properties which cause the cell to appear striped or striated. In smooth muscle cells, this alignment is absent, hence there are no apparent striations and the cells are called smooth.

Appearance

The names of the various sub-regions of the sarcomere are based on their relatively lighter or darker appearance when viewed through the light microscope. Each sarcomere is delimited by two very dark colored bands called Z-discs or Z-lines (from the German zwischen meaning between). These Z-discs are dense protein discs that do not easily allow the passage of light. The T-tubule is present in this area. The area between the Z-discs is further divided into two lighter colored bands at either end called the I-bands, and a darker, grayish band in the middle called the A band.

The I bands appear lighter because these regions of the sarcomere mainly contain the thin actin filaments, whose smaller diameter allows the passage of light between them. The A band, on the other hand, contains mostly myosin filaments whose larger diameter restricts the passage of light. A stands for anisotropic and I for isotropic, referring to the optical properties of living muscle as demonstrated with polarized light microscopy.

The parts of the A band that abut the I bands are occupied by the both actin and myosin filaments (where they interdigitate as described above). Also within the A band is a relatively brighter central region called the H-zone (from the German helle, meaning bright) in which there is no actin/myosin overlap when the muscle is in a relaxed state. Finally, the A band is bisected by a dark central line called the M-line (from the German mittel meaning middle).

Action

When a muscle contracts, the actin is pulled along myosin toward the center of the sarcomere until the actin and myosin filaments are completely overlapped. The H zone becomes smaller and smaller due to the increasing overlap of actin and myosin filaments, and the muscle shortens. Thus when the muscle is fully contracted, the H zone is no longer visible (as in the bottom diagram, left). Note that the actin and myosin filaments themselves do not change length, but instead slide past each other. This is known as the sliding filament theory of muscle contraction.

Sarcoplasm

The Sarcoplasm of a muscle fiber is comparable to the cytoplasm of other cells, but it houses unusually large amounts of glycosomes (granules of stored glycogen) and significant amounts of myoglobin, an oxygen binding protein. The calcium concentration in sarcoplasma is also a special element of the muscular fiber by means of which the contractions takes place and regulates.

Other than the fact that it contains mostly myofibrils, its contents are otherwise comparable to those of the cytoplasm of other cells. It has a Golgi apparatus, near the nucleus, mitochondria just on the inside of the cytoplasmic membrane or sarcolemma, as well as a smooth endoplasmic reticulum organized in an extensive network.

Protein 101: How Much Do You Need & Best Sources of Protein

What do you need protein for? How much protein do you need? Are high protein intakes safe for your kidneys? What are the best sources of protein? This post will answer any question you might have about protein.

Why Do You Need Protein? Proteins are building blocks. Muscle, skin, hair, They're all made of protein. Benefits of reaching your daily protein needs:

· Build Muscle. Since you need protein to build muscle, eating enough protein will ensure your body has what it needs to build new one.

· Maintain Muscle. Getting your body the protein it needs will improve muscle recovery and prevent muscle breakdown from exercising.

· Fat Loss. Protein has the highest thermic effect: your body burns more calories digesting proteins than carbs or fat. Protein also satiates: you feel full longer after eating a protein-rich meal. Both help fat loss.

How Much Protein Do You Need? The United States RDA is 0.8g/kg or 0.4g/lbs. This is 80g protein per day if you weigh 200lbs. But this recommendation is based on studies done on average, sedentary people.

The minimum if you train hard is 1g protein per pound of body-weight per day. That's 200g daily protein if you weigh 200lbs. You'll reach this amount easily by eating a whole protein source with each meal.

Protein Myths. Here's some urban legend on protein that you'll hear in gyms and probably also from friends, colleagues & crabs.

· Protein Is Bad for Your Kidneys. There's no data suggesting that high protein intakes cause the onset of kidney dysfunctions in healthy adults. There aren't even correlational studies. Try to find them.

· Protein Causes Weight Gain. Increasing your protein intake or drinking whey shakes won't make you gain weight unless you increase your daily calorie intake. Read how to gain weight for skinny guys.

· You Can Digest Max 30g Protein/Meal. Your body can digest & absorb pretty much anything you give it. Read the post how much protein can you absorb per meal for more info.

Best Sources of Protein. Vary your protein sources so you get the full range of amino acids. Here are some of the best & most popular sources of protein which also have been a staple of my diet for years.

· Red Meat. Steaks & ground round. Top round, sirloin.

· Poultry. Chicken breast, ground turkey, whole chicken.

· Fish. Canned tuna, mackerel, salmon.

· Dairy. Milk, cottage cheese, plain low fat yogurt, quark cheese, whey.

· Eggs. Whole eggs, scrambled eggs. Don't worry about cholesterol.

· Nuts. Walnuts, almonds, cashew, pistachio

Example Diet. Here's an example diet that will provide you with 200g protein. Again: eat a whole protein source with each meal and you'll reach your daily protein requirement easily. This diet fits the 8 nutrition rules.

Ø Breakfast. 3 whole eggs, veggies, orange, green tea.

Ø Snack. 100g Plain fat free yogurt, 1 scoop whey, apple.

Ø Lunch. 1 Can of tuna, roman lettuce, olive oil.

Ø Snack. 100g Mixed nuts, peer.

Ø Post Workout Shake. 1 Scoop whey, 300ml milk, oats, banana.

Ø Dinner. 150g Chicken breast, spinach, baby carrots.

Ø Pre bed. 200g Cottage cheese, berries, flax seeds, fish oil.

Protein is acidic. Eat plenty of veggies, ideally with each meal, to combat acidity. This prevents muscle & bone loss. The most alkaline food is spinach.