Genetic deficiencies in the creatine biosynthetic pathway lead to various severe neurological defects.[26] Clinically, there are three distinct disorders of creatine metabolism. Deficiencies in the two synthesis enzymes can cause L-arginine:glycine amidinotransferase deficiency caused by variants in GATM and guanidinoacetate methyltransferase deficiency, caused by variants in GAMT. Both biosynthetic defects are inherited in an autosomal recessive manner. A third defect, creatine transporter defect, is caused by mutations in SLC6A8 and inherited in a X-linked manner. This condition is related to the transport of creatine into the brain.[27]
Change things up. After six or more weeks of consistent strength training, which is about the amount of time it takes to start seeing improvement in your body, you can change your routine to make it more difficult. Lifting the same weights for the same exercises every week will keep your body in the same place. You can modify weights or repetitions, choose different exercises, or change the order in which you do them. You only have to make one change at a time to make a difference, although more is often better. 
The basic principles of weight training are essentially identical to those of strength training, and involve a manipulation of the number of repetitions (reps), sets, tempo, exercise types, and weight moved to cause desired increases in strength, endurance, and size. The specific combinations of reps, sets, exercises, and weights depends on the aims of the individual performing the exercise.
For example, say you are pursuing a muscle power objective in which you have decided to perform 3 sets of 8 repetitions each. You'll want to make sure you don't add too much weight so that you are able to perform all 8 repetitions before your muscles are too tired to finish the set. Conversely you'll want to make sure you add enough weight so that you are not simply breezing past the repetitions and finish your sets of plenty of energy still left in the tank. While it may take a few workout sessions to find the right combination, once you'll do it'll be easy to monitor and increase weight as you progress.
Now, if you are somebody that is more of the “do-it-yourself” type, check out our self-paced online course, the Nerd Fitness Academy. The Academy has 20+ workouts for both bodyweight or weight training, a benchmark test to determine your starting workout, HD demonstrations of every movement, boss battles so you know when you to level up your routine, meal plans, a questing system, and supportive community.
The amount of testosterone synthesized is regulated by the hypothalamic–pituitary–testicular axis (see figure to the right).[133] When testosterone levels are low, gonadotropin-releasing hormone (GnRH) is released by the hypothalamus, which in turn stimulates the pituitary gland to release FSH and LH. These latter two hormones stimulate the testis to synthesize testosterone. Finally, increasing levels of testosterone through a negative feedback loop act on the hypothalamus and pituitary to inhibit the release of GnRH and FSH/LH, respectively.

The US FDA reports 50,000 health problems a year due to dietary supplements [14] and these often involve bodybuilding supplements.[15] For example, the "natural" best-seller Craze, 2012's "New Supplement of the Year" by bodybuilding.com, widely sold in stores such as Walmart and Amazon, was found to contain N,alpha-Diethylphenylethylamine, a methamphetamine analog.[16] Other products by Matt Cahill have contained dangerous substances causing blindness or liver damage, and experts say that Cahill is emblematic for the whole industry.[17]


The creatine transporter (CrT) is positively regulated by proteins known to be involved in sensing and responding to the cellular energy state, including the mammalian target of rapamycin (mTOR[158]). Upon activation, mTOR stimulates SGK1 and SGK3[159][160] to act upon PIKfyve[161] and subsequently PI(3,5)P2[162] to increase CrT activity.[161] Beyond mTOR, SGK1 also is stimulated by intracellular calcium[163] and a lack of oxygen (ischemia).[164] Because transient ischemia is associated with increased reactive oxygen species (ROS) production after blood flow is restored (reperfusion) it has been hypothesized that muscle contraction may increase creatine uptake through a similar ROS-mediated mechanism.[165]


Using too much weight, too soon; always start lower than your expected ability and work your way up that first workout. If your form suffers, you are swinging the weight, or using momentum, this indicates you may be using too much weight. Greater momentum increases the potential for injury and reduces the effectiveness to the muscle group being targeted.

Don’t make the mistake of trying to bulk up when you should be on a diet. While you might have muscle on your mind, most people need to get leaner first. If you’re fat and you start eating for size, you’re only going to get fatter. Get rid of the excess blubber first, to the point where you can see some abs, and then worry about getting big. You should be as low as 12% body fat before you change your diet up to focus on mass gain. That will ensure that your insulin sensitivity is high. When it is, you can eat more carbs and your body won’t store them as fat.

The Branched-Chain Amino Acids, BCAAs for short, are leucine, valine and isoleucine.  Essentially, its a form of protein powder for muscle gain or other uses. These essential amino acids are not made by the body but are found in foods such as meats, dairy products and legumes. In medicine, BCAAs are used for a number of conditions, however, for many uses, further research is necessary to determine whether or not treatment is effective.


Entry into neural tissues in general is mediated by the secondary creatine transporter (CrT-2) known as SLC6A10,[186] which is the same transporter that is active in a male’s testicles.[145] CrT-2 belongs to the family of SLC6 transporters that act to move solutes across the membrane by coupling transport with sodium and chloride.[187][188] Genetic deletions in the 16p11.2 region, which encodes both SLC6A8[189] and SLC6A10[186] can result in severe mental retardation in humans and is one of the causes of “Creatine Deficiency Syndrome.” Creatine Deficiency Syndrome is not only caused by lack creatine transporter expression, however, as creatine synthesis is also critical for neural function.[190].[189] Retardation caused by defective creatine synthesis[31] can be reversed with creatine supplementation and dietary changes.[191]


Liquid creatine has been shown to be less effective than creatine monohydrate.[69] This reduced effect is due to the passive breakdown of creatine over a period of days into creatinine, which occurs when it is suspended in solution.[70] This breakdown is not an issue for at-home use when creatine is added to shakes, but it is a concern from a manufacturing perspective in regard to shelf-life before use.
Back in the 1970s, scientists discovered that taking creatine in supplement form might enhance physical performance. In the 1990s, athletes started to catch on, and creatine became a popular sports supplement. The supplement is particularly popular among high school, college, and professional athletes, especially football and hockey players, wrestlers, and gymnasts. 
Because I don’t want you to have to waste all the years and money that I did (not to mention the surgeon’s bills), I came up with a method of training and eating specifically for skinny-fat, injury-prone hard-gainers: guys who historically can’t gain muscle doing the workouts they find in magazines or on blogs. It’s also perfect for all guys over age 35 who need to be smarter with their training as they age.

More specifically, you can expect to end up in the upper half of these ranges ONLY if you are a beginner, younger, and/or have amazing genetics. You can expect to end up in the lower half of these ranges if you are an intermediate or advanced trainee, older, and/or have poor genetics. The average person can expect to end up somewhere in the middle. Additional details here: How Much Muscle Can You Gain?
This increased permeability is noted in glioma cells, where it exerts anti-cancer effects related to cell swelling,[99][100] and in other membranes, such as breast cancer cells[101] and skeletal (contractile) muscle cells.[102] The kinetics of cyclocreatine appear to be first-order,[101] with a relative Vmax of 90, Km of 25mM and a KD of 1.2mM.[103]
Synthesis primarily takes place in the kidney and liver, with creatine then being transported to the muscles via the blood. The majority of the human body's total creatine and phosphocreatine stores is located in skeletal muscle, while the remainder is distributed in the blood, brain, and other tissues.[17][18][20] Typically, creatine is produced endogenously at an estimated rate of about 8.3 mmol or 1 gram per day in young adults.[16][17] Creatine is also obtained through the diet at a rate of about 1 gram per day from an omnivorous diet.[17][18] Some small studies suggest that total muscle creatine is significantly lower in vegetarians than non-vegetarians, as expected since foods of animal origin are the primary source of creatine. However, subjects happened to show the same levels after using supplements.[21]
Stronger muscles improve performance in a variety of sports. Sport-specific training routines are used by many competitors. These often specify that the speed of muscle contraction during weight training should be the same as that of the particular sport. Sport-specific training routines also often include variations to both free weight and machine movements that may not be common for traditional weightlifting.

If you are somebody that is tired of not getting results, wants to avoid trial-and-error, or you just want to be told exactly what to do to reach your goals, check out our popular 1-on-1 coaching program. You’ll work with our certified NF instructors who will get to know you better than you know yourself and program your workouts and nutrition strategy for you.
Topical testosterone, specifically gels, creams and liquids, may transfer to others. Women and children are most at risk of harmful effects from contact with them. You should take care to cover the area and wash your hands well after putting on the medication. Be careful not to let the site with the topical TT touch others because that could transfer the drug.
Synthesis primarily takes place in the kidney and liver, with creatine then being transported to the muscles via the blood. The majority of the human body's total creatine and phosphocreatine stores is located in skeletal muscle, while the remainder is distributed in the blood, brain, and other tissues.[17][18][20] Typically, creatine is produced endogenously at an estimated rate of about 8.3 mmol or 1 gram per day in young adults.[16][17] Creatine is also obtained through the diet at a rate of about 1 gram per day from an omnivorous diet.[17][18] Some small studies suggest that total muscle creatine is significantly lower in vegetarians than non-vegetarians, as expected since foods of animal origin are the primary source of creatine. However, subjects happened to show the same levels after using supplements.[21]

There are also many other variations of squats you can try. Squats can be done with weights held in the front of your body or behind your back, using dumbbells or a stability ball, with your arms held overhead or parallel to the floor, using a chair or wall for support if you’re more limited, held in place while you focus on breathing (as is done in yoga during “chair pose”), and in other ways. Pistol squats are also a great workout for the entire legs and hips. Pistols are one-legged squats with one relaxed hamstring and calf and the other leg straight out in front of you as you lower down.
As scientific research progressed, it became apparent that the best types of protein came from milk and eggs. That led to the next great revolution in sports nutrition, namely the engineered food, pioneered by Scott Connelly, M.D., a critical care specialist from Northern California who teamed with a young entrepreneur named Bill Phillips from Golden, Colorado.

Depression is a common psychological disorder affecting millions of people around the world. It results in severe sadness, loss of interest in activities, and difficulty performing daily tasks. It may be caused by common factors such as life events, genetic predisposition, conflict, and other psychological problems. However, low testosterone remains an, often missed cause of depression. In persons with low testosterone levels and depression, treatment includes testosterone replacement therapy as well as supportive measures including dietary modifications, increased activity, and use of natural supplements such as Tongkat Ali.

Bodybuilding developed in the late 19th century, promoted in England by German Eugen Sandow, now considered as the "Father of Bodybuilding". He allowed audiences to enjoy viewing his physique in "muscle display performances". Although audiences were thrilled to see a well-developed physique, the men simply displayed their bodies as part of strength demonstrations or wrestling matches. Sandow had a stage show built around these displays through his manager, Florenz Ziegfeld. The Oscar-winning 1936 musical film The Great Ziegfeld depicts the beginning of modern bodybuilding, when Sandow began to display his body for carnivals.
Phosphocreatine is known to be a major source of energy for cardiac tissue alongside fatty acids, which are dominant under periods of normoxia (normal oxygen) while phosphocreatine becomes more important in periods of hypoxic stress.[281][282][283] The entire CK system plays a role in the recovery of the heart following ischemic/hypoxic stress, since blocking CK activity impairs recovery[284][285] and overexpressing CK activity promotes it.[286] This is due to the heart tissue needing high energy phosphate groups at this time, and the ischemic stress reduces CK activity and the ability of CK to donate these groups.[287][288]
The motor proteins actin and myosin generate the forces exerted by contracting muscles. Current recommendations suggest that bodybuilders should consume 25–30% of protein per total calorie intake to further their goal of maintaining and improving their body composition.[30] This is a widely debated topic, with many arguing that 1 gram of protein per pound of body weight per day is ideal, some suggesting that less is sufficient, while others recommending 1.5, 2, or more.[31] It is believed that protein needs to be consumed frequently throughout the day, especially during/after a workout, and before sleep.[32] There is also some debate concerning the best type of protein to take. Chicken, turkey, beef, pork, fish, eggs and dairy foods are high in protein, as are some nuts, seeds, beans, and lentils. Casein or whey are often used to supplement the diet with additional protein. Whey protein is the type of protein contained in many popular brands of protein supplements and is preferred by many bodybuilders because of its high Biological Value (BV) and quick absorption rates. Whey protein also has a bigger effect than casein on insulin levels, triggering about double the amount of insulin release.[33] That effect is somewhat overcome by combining casein and whey. Bodybuilders are usually thought to require protein with a higher BV than that of soy, which is additionally avoided due to its claimed estrogenic properties. Still, some nutrition experts believe that soy, flax seeds and many other plants that contain the weak estrogen-like compounds or phytoestrogens, can be used beneficially, as phytoestrogens compete with estrogens for receptor sites in the male body and can block its actions. This can also include some inhibition of pituitary functions while stimulating the P450 system (the system that eliminates hormones, drugs and metabolic waste product from the body) in the liver to more actively process and excrete excess estrogen.[34][35] Cortisol decreases amino acid uptake by muscle, and inhibits protein synthesis.[36]
Escolar, D. M., Buyse, G., Henricson, E., Leshner, R., Florence, J., Mayhew, J., Tesi-Rocha, C., Gorni, K., Pasquali, L., Patel, K. M., McCarter, R., Huang, J., Mayhew, T., Bertorini, T., Carlo, J., Connolly, A. M., Clemens, P. R., Goemans, N., Iannaccone, S. T., Igarashi, M., Nevo, Y., Pestronk, A., Subramony, S. H., Vedanarayanan, V. V., and Wessel, H. CINRG randomized controlled trial of creatine and glutamine in Duchenne muscular dystrophy. Ann Neurol 2005;58(1):151-155. View abstract.
Standing with your feet hips distance apart, hold a barbell or free weights at shoulder height (either the barbell resting above your shoulder blades on your back, or free weights resting on top of your shoulder muscles held in front of you). Keeping your spine in a neutral position move into the squat by retracting your hips and pulling them backward. Hinging at your hips, bend your knees until your thighs come almost parallel to the ground (knees should be directly over your feet). Then push back up until your back is straight and repeat 5–10 times depending on the weight you’re using.

If you're a beginner, start with a basic total body strength workout to build a strong foundation in all your muscle groups. Taking this time will help you figure out any weaknesses you have, as well as any issues you may need to address with your doctor, and learn the basic exercises you need for a strong, fit body. Your first step is to figure out where you're going to exercise.

These supplements can vary considerably from product to product in ingredients, serving sizes, and more. But the goal of each of them is generally quite similar. Most bodybuilding supplements are designed to help stimulate new muscle growth, cut away excess fat, and improve the recovery process so that you can get the most out of each trip to the gym.
It’s true—your genes can play a role when it comes to building muscle. In general, there are two types of muscle fibers: Type I, which are slow twitch, and Type II, which are fast twitch. Depending on which you have more of, you may have an easier or harder time gaining muscle. “Fast twitch muscle fibers are two times as thick as slow twitch muscle fibers, lending to the overall thickness of the muscle without any activity,” explains Lovitt. “Those people with a genetic predisposition of a high percentage of these fibers can increase muscle size very easily while the people with a higher percentage of slow twitch muscle fibers have to work really hard to put on mass.” It’s the reason why a world-class sprinter genetically has more fast twitch muscle fibers than a world-class marathoner—it comes down to what we’re born with.
These protective effects are similar to those seen with trimethylglycine, since they both cause an increase in liver concentrations of phosphatidylcholine (PC, causing an increase in vLDL production and efflux of triglycerides from the liver).[497] Both TMG and creatine are thought to work indirectly by preserving SAMe concentrations,[125][498] since PC synthesis requires SAMe as well (via PEMT[499]) and genes involved in fatty acid metabolism in the liver that were not affected by the diet (VLCAD and CD36) were unaffected by creatine.[125]
In addition to the basic principles of strength training, a further consideration added by weight training is the equipment used. Types of equipment include barbells, dumbbells, pulleys and stacks in the form of weight machines, and the body's own weight in the case of chin-ups and push-ups. Different types of weights will give different types of resistance, and often the same absolute weight can have different relative weights depending on the type of equipment used. For example, lifting 10 kilograms using a dumbbell sometimes requires more force than moving 10 kilograms on a weight stack if certain pulley arrangements are used. In other cases, the weight stack may require more force than the equivalent dumbbell weight due to additional torque or resistance in the machine. Additionally, although they may display the same weight stack, different machines may be heavier or lighter depending on the number of pulleys and their arrangements.

The creatine kinase system appears to be detectable in endothelial cells.[314][315] Under basal conditions, creatine itself is expressed at around 2.85+/-0.62μM[316] (three-fold higher than HUVEC cells[314]). When incubating the medium with 0.5mM creatine, endothelial cells can take up creatine via the creatine transporter (SLC6A8) and increase both creatine (almost doubling) and phosphocreatine (nearly 2.5-fold) concentrations.[316]

Universal Creatine Powder is 100% pure creatine monohydrate. Universal Nutrition supplies us with a pure, quick to absorb blend in the creatine supplement world today. Use Universal Creatine and see how you can increase the size of your muscles and improve in strength as well as endurance during your workouts. Don't let fatigue stop you from becoming who you want to be. Keep Reading »
The largest determiner of your metabolic rate is actually your total body mass. “The more cells, even fat cells, in your body, the more furnaces you have burning at any given time,” Dr. Church says. Think of it this way: It takes more juice to charge your tablet than it does to charge your phone. People who are taller and have a larger bone structure, therefore, will have a higher BMR than people who are shorter and have a slimmer build. While you can control your body mass to some extent by gaining or losing weight, you can’t change your height or your bone structure. All in all, most of a person’s BMR is determined by genetic factors, Dr. Church says.
The brain is also affected by this sexual differentiation;[13] the enzyme aromatase converts testosterone into estradiol that is responsible for masculinization of the brain in male mice. In humans, masculinization of the fetal brain appears, by observation of gender preference in patients with congenital diseases of androgen formation or androgen receptor function, to be associated with functional androgen receptors.[99]
Related to exercise and fitness, BCAAs are taken to help reduce muscle breakdown, which is why they may be known as muscle building supplements. Leucine, in particular, is known for playing an important role in muscle protein synthesis, which can help with muscle gain and maintenance. Some also claim that BCAAs can enhance performance, although many studies also refute this claim.
After all, if you’re doing more reps in a set, the weight would obviously be lighter and the intensity level lower. If you’re doing fewer reps in a set, the weight is obviously heavier and the intensity is higher. In addition, how close you come to reaching failure – aka the point in a set when you are unable to complete a rep – also plays a role here.

I’m telling you all of this because no matter who you are, keeping your testosterone levels balanced is more important now than ever before. Modern living has not been kind to our hormones. In American men, serum testosterone levels have declined by about 1% each year for the past 30 years [5], and you can make a few educated guesses about why. Hormone-disrupting chemicals are more prevalent than ever before, physical activity is less and less common, veganism is popular (I was a raw vegan for a while), and many doctors insist on pushing a low-fat, low-cholesterol diet for health (by the way, the concept of a low-fat diet began in the mid-70s, shortly before the nationwide testosterone decline. It could be a coincidence, but I doubt it).


Anti-depressive effects have been noted in woman with major depressive disorder when 5g of creatine monohydrate was supplemented daily for 8 weeks in combination with an SSRI. Benefits were seen at week two and were maintained until the end of the 8-week trial.[253] The improvement in depressive symptoms was associated with significantly increased prefrontal cortex levels of N-acetylaspartate, a marker of neuronal integrity,[254] and rich club connections, which refers to the ability of nerons to make connections to one another.[255]

These complete proteins include all of the essential amino acids that the body cannot produce itself. Different proteins, such as whey and casein, egg and soy have different absorption rates. Whether you should favor one over another for muscle building is still a subject of popular and scientific debate, although whey protein isolate, a more rapidly absorbed protein, has some support from various scientific studies. For protein powders, assess the value by checking out the protein listed on the label. Combined with resistance training, sufficient protein consumption along with an appropriate diet can lead to increased muscle and reduced body fat. You should read more about The Bodybuilding Diet for supplement timing issues before and after training. 
2-[carbamimidoyl(methyl)amino]acetic acid, Cr, Creatin, Creatina, Créatine, Créatine Anhydre, Creatine Anhydrous, Creatine Citrate, Créatine Citrate, Creatine Ethyl Ester, Créatine Ethyl Ester, Creatine Ethyl Ester HCl, Créatine Ethyl Ester HCl, Creatine Gluconate, Creatine Hydrochloride, Créatine Kré Alkaline, Creatine Malate, Créatine Malate, Creatine Monohydrate, Créatine Monohydrate, Créatine Monohydratée, Creatine Pyroglutamate, Créatine Pyroglutamate, Creatine Pyruvate, Créatine Pyruvate, Dicreatine Malate, Dicréatine Malate, Di-Creatine Malate, Éthyle Ester de Créatine, Glycine, Kreatin, Kre-Alkalyn Pyruvate, Malate de Tricréatine, N-(aminoiminométhyl)-N-Méthyl, N-(aminoiminomethyl)-N methyl glycine, N-amidinosarcosine, Phosphocreatine, Phosphocréatine, Tricreatine HCA, Tricréatine HCA, Tricreatine Malate, Tricréatine Malate.


After the ingestion of 5g creatine in otherwise healthy humans, serum levels of creatine were elevated from fasting levels (50-100µM) to 600-800µM within one hour after consumption.[135] The receptor follows Michaelis-Menten kinetics with a Vmax obtained at concentrations higher than 0.3-0.4mmol/L,[136] with prolonged serum concentrations above this amount exerting most of its saturation within two days.[137]
Like other steroid hormones, testosterone is derived from cholesterol (see figure).[128] The first step in the biosynthesis involves the oxidative cleavage of the side-chain of cholesterol by cholesterol side-chain cleavage enzyme (P450scc, CYP11A1), a mitochondrial cytochrome P450 oxidase with the loss of six carbon atoms to give pregnenolone. In the next step, two additional carbon atoms are removed by the CYP17A1 (17α-hydroxylase/17,20-lyase) enzyme in the endoplasmic reticulum to yield a variety of C19 steroids.[129] In addition, the 3β-hydroxyl group is oxidized by 3β-hydroxysteroid dehydrogenase to produce androstenedione. In the final and rate limiting step, the C17 keto group androstenedione is reduced by 17β-hydroxysteroid dehydrogenase to yield testosterone.
How to use this list: The exercises below are demonstrated by Amanda Butler, certified personal trainer and creator of the Butler Method for NeoU Fitness, so you can master the perfect form. Aim to do these moves three days a week. Perform one to three sets of 10 to 20 repetitions, depending on your fitness level. You will need a looped resistance band. An exercise mat is optional. The last move is a bonus drill you can perform on the bike.
Sound complicated? Fortunately, there's an easy rule of thumb for increasing your training volume: For each exercise, perform three to six sets of six to 12 reps, resting for 30 to 90 seconds between each set, she says. The weight used should be enough that you can get out your last reps with proper form but wouldn't be able to perform any additional reps.
Creatine, the amino acid, naturally helps your body produce more adenosine triphosphate, or ATP, a small molecule that’s actually your body's primary energy source. But research shows that your body is only capable of storing enough ATP for 8 to 10 seconds of high-intensity exercise — and after that, it needs to produce new ATP for you to continue. (9) 

Weight training has also been shown to benefit dieters as it inhibits lean body mass loss (as opposed to fat loss) when under a caloric deficit. Weight training also strengthens bones, helping to prevent bone loss and osteoporosis. By increasing muscular strength and improving balance, weight training can also reduce falls by elderly persons. Weight training is also attracting attention for the benefits it can have on the brain, and in older adults, a 2017 meta analysis found that it was effective in improving cognitive performance.[38]
Although some men believe that taking testosterone medications may help them feel younger and more vigorous as they age, few rigorous studies have examined testosterone therapy in men who have healthy testosterone levels. And some small studies have revealed mixed results. For example, in one study healthy men who took testosterone medications increased muscle mass but didn't gain strength.
Eat 1.5–3 grams of carbs per pound of your body weight. As with fat, this amount can vary greatly, depending on your personal needs and preferences, so consider these numbers only a starting point. If you’re very skinny and feel that you handle carbs well (i.e. you can eat a lot of them without getting fat), go ahead and eat according to the higher end of the spectrum. The same applies if you’re desperate to gain weight—you should increase your carb intake. If you’re prone to weight gain or feel lethargic on higher carbs, you should eat fewer of them. Again, see our keto guide for more details and options.
How much weight? Start with a pair of light dumbbell hand weights (2 to 3 pounds for women and 5 to 8 pounds for men). If you can’t do 12 repetitions (or reps are the number of times you do the exercise) the weight is too heavy. If your muscles don’t feel tired after 12 reps, it’s too light. Adjustable weights that can be strapped to wrists or ankles may be convenient if you have arthritis in your hands. You can also use home or gym weight machines, or resistance bands.
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