There is a great amount of research published on creatine supplementation; protocols of administration, forms of creatine, as well as potential side effects. Despite this, the mechanisms by which creatine acts in the human body to improve physical and cognitive performance are still not clear. The main objectives of this review are to analyze the more recent findings on the effects and mechanisms of creatine supplementation in sports and health. As a secondary purpose, we will analyze the most recommended protocols of ingestion and its potential side effects.
Testosterone is the principle sex hormone responsible for the development of reproductive function in male vertebrates. Testosterone is one of the hormones referred to as androgens, which are also known of as anabolic steroids. As a steroid hormone, testosterone is derived from cholesterol and the structure of this hormone is similar across all mammals, reptiles, birds and fish.
You see, there is only so much muscle that the human body is capable of building in a given period of time. So, if you supply your body with MORE calories than it’s actually capable of putting towards the process of building new muscle… it’s not going to magically lead to additional muscle being built. It’s just going to lead to additional fat being gained.
Testosterone is necessary for normal sperm development. It activates genes in Sertoli cells, which promote differentiation of spermatogonia. It regulates acute HPA (hypothalamic–pituitary–adrenal axis) response under dominance challenge. Androgen including testosterone enhances muscle growth. Testosterone also regulates the population of thromboxane A2 receptors on megakaryocytes and platelets and hence platelet aggregation in humans.
^ "Popular sports supplements contain meth-like compound". USA Today. October 25, 2013. Cohen said researchers informed the FDA in May about finding the new chemical compound in Craze. The team found the compound — N,alpha-diethylphenylethylamine — has a structure similar to methamphetamine, a powerful, highly addictive, illegal stimulant drug. They believe the new compound is likely less potent than methamphetamine but greater than ephedrine.
In people with COPD given either glucose placebo (40.7g) or creatine supplementation (5.7g creatine with 35g glucose) thrice daily for two weeks followed by a single dose for ten weeks, supplementation was associated with improvements in muscular strength and endurance, but not cardiovascular exercise potential. A later trial of larger power using a loading phase of 22g creatine with a maintenance phase of 3.76g during rehabilitative exercise failed to replicate the improvements in skeletal muscle performance despite increased body weight seen with creatine, and the failure to improve cardiovascular performance during aerobic exercise seen in both aforementioned studies has been replicated elsewhere after eight weeks supplementation, during which muscular performance was, again, unaffected.
Creatine is only taken up by its transporter, and changes in the activity level of this transporter are wholly causative of changes in creatine uptake. The transporter is regulated by mostly cytosolic factors as well as some external factors that affect creatine transport activity,  including extracellular creatine. Agents affecting creatine transport are further divided into positive regulators (those that increase activity of the transporter) and negative regulators (those that suppress activity).
More recent studies on the regulation of CrT creatine transport activity have identified the protein kinase (Janus-Activating Kinase 2) JAK2, which suppresses the rate of creatine uptake via CrT without affecting creatine binding. JAK2 is a regulatory protein involved in stabilizing the cellular membrane and controlling water concentrations in response to osmotic stress. Similar to c-Src (a positive creatine transport regulator), Jak2 can also be activated by growth hormone signaling. The growth hormone receptor seems to activate these two factors independently, as gh-mediated activation of c-Src does not require JAK2. Given that c-Src is a positive regulator of CrT, JAK2 is a negative regulator, and the fact that downstream signals from both are induced by growth hormone, it is tempting to speculate that JAK2 activation downstream of the gh receptor may function as a homeostatic response to limit c-src induced creatine uptake. This has not been studied, however, and the effects of gh-induced JAK2 signaling on CrT activity have not been examined.
In regard to practical interventions, concurrent glycogen loading has been noted to increase creatine stores by 37-46% regardless of whether the tissue was exercised prior to loading phase. It is important to note, however, that creatine levels in response to the creatine loading protocol were compared in one glycogen-depleted leg to the contralateral control leg, which was not exercised. This does not rule out a possible systemic exercise-driven increase in creatine uptake, and the increase in creatine noted above was larger than typically seen with a loading protocol (usually in the 20-25% range). Consistent with an exercise-effect, others have reported that exercise itself increases creatine uptake into muscle, reporting 68% greater creatine uptake in an exercised limb, relative to 14% without exercise.
The lower the rep range (and therefore the higher the intensity and the heavier the weight), the more rest there should be between sets. So most of the time, exercises being done in the 5-8 rep range need longer rest periods than exercises being done in the 8-10 rep range, which need longer rest periods than exercises being done in the 10-15 rep range.
In contrast to the above null effects, ingestion of creatine both before and after a workout (alongside protein and carbohydrate) over 10 weeks seems to promote muscle growth more than the same supplement taken in the morning, farther away from the time of the workout. The benefits of creatine around the workout, relative to other times, have been hypothesized to be related to an upregulation of creatine transport secondary to muscle contraction, a known phenomena.
Creatine supplementation appears to attenuate decreases in GLUT4 expression seen with immobility and may increase GLUT4 expression during exercise. While it seems capable of increasing GLUT4 during resting conditions, it has failed to reach significance, suggesting that creatine supplementation works best with some stimuli associated with exercise.
The benefits of weight training overall are comparable to most other types of strength training: increased muscle, tendon and ligament strength, bone density, flexibility, tone, metabolic rate, and postural support. This type of training will also help prevent injury for athletes. There are benefits and limitations to weight training as compared to other types of strength training. Contrary to popular belief, weight training can be beneficial for both men and women.
Creatine transport has been shown to increase when muscle creatine stores are depleted. This was only noted to occur in muscle with particular fiber types (soleus and red gastrocnemius), while other fiber types, such as white grastrocnemius, did not show any clear trend. This indicates that transport in relation to total creatine levels varies across different muscle fiber types.
Sports where strength training is central are bodybuilding, weightlifting, powerlifting, and strongman, highland games, hammer throw, shot put, discus throw, and javelin throw. Many other sports use strength training as part of their training regimen, notably: American football, baseball, basketball, football, hockey, lacrosse, mixed martial arts, rowing, rugby league, rugby union, track and field, boxing and wrestling.
The gluteus maximus arises from the posterior gluteal line of the inner upper ilium, and the rough portion of bone including the crest, immediately above and behind it; from the posterior surface of the lower part of the sacrum and the side of the coccyx; from the aponeurosis of the erector spinae (lumbodorsal fascia), the sacrotuberous ligament, and the fascia covering the gluteus medius. The fibers are directed obliquely downward and lateralward; The muscle has two insertions: Those forming the upper and larger portion of the muscle, together with the superficial fibers of the lower portion, end in a thick tendinous lamina, which passes across the greater trochanter, and inserts into the iliotibial band of the fascia lata; and the deeper fibers of the lower portion of the muscle are inserted into the gluteal tuberosity between the vastus lateralis and adductor magnus. Its action is to extend and to laterally rotate the hip, and also to extend the trunk.
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.
XPI's Myotein is a premium protein blend that features Casein, Whey Protein Isolate and Whey Protein Concentrate. That makes 25 grams of protein per serving of the most advanced protein formula, engineered for fast absorption and utilization. Each scoop also contains 2 grams fat and 2 grams carbs, and additional digestive enzymes for increased bio-availability. With several creamy flavors to choose from, Myotein is rated one of the best tasting protein powders on the market. Keep Reading »
Total levels of testosterone in the body are 264 to 916 ng/dL in men age 19 to 39 years, while mean testosterone levels in adult men have been reported as 630 ng/dL. Levels of testosterone in men decline with age. In women, mean levels of total testosterone have been reported to be 32.6 ng/dL. In women with hyperandrogenism, mean levels of total testosterone have been reported to be 62.1 ng/dL.
This basic form of creatine comes in two forms, one of which involves the removal of the monohydrate (which results in creatine anhydrous) that converts to creatine monohydrate in an aqueous environment, but due to the exclusion of the monohydrate it is 100% creatine by weight despite creatine monohydrate being 88% creatine by weight, as the monohydrate is 12%. This allows more creatine to be present in a concentrated formula, like capsules.
Weight training also requires the use of 'good form', performing the movements with the appropriate muscle group, and not transferring the weight to different body parts in order to move greater weight (called 'cheating'). Failure to use good form during a training set can result in injury or a failure to meet training goals; since the desired muscle group is not challenged sufficiently, the threshold of overload is never reached and the muscle does not gain in strength. At a particularly advanced level; however, "cheating" can be used to break through strength plateaus and encourage neurological and muscular adaptation.
A retrospective study , that examined the effects of long lasting (0.8 to 4 years) CM supplementation on health markers and prescribed training benefits, suggested that there is no negative health effects (including muscle cramp or injuries) caused by long term CM consumption. In addition, despite many anecdotal claims, it appears that creatine supplementation would have positive influences on muscle cramps and dehydration . Creatine was found to increase total body water possibly by decreasing the risk of dehydration, reducing sweat rate, lowering core body temperature and exercising heart rate. Furthermore, creatine supplementation does not increase symptoms nor negatively affect hydration or thermoregulation status of athletes exercising in the heat [83,84]. Additionally, CM ingestion has been shown to reduce the rate of perceived exertion when training in the heat .
Honestly, I did a lot of research on this one, because I wanted to find a single group of people who should not strength train. I even found studies on how strength training can be beneficial for paraplegics. Not to mention it can be safe for children, adolescents, and pregnant women. Obviously, you should take a break from strength training if you’re injured, and always check with your doctor before you start any sort of strength training program, but it’s natural for us, as humans, to move around and carry things.
The largest amounts of testosterone (>95%) are produced by the testes in men, while the adrenal glands account for most of the remainder. Testosterone is also synthesized in far smaller total quantities in women by the adrenal glands, thecal cells of the ovaries, and, during pregnancy, by the placenta. In the testes, testosterone is produced by the Leydig cells. The male generative glands also contain Sertoli cells, which require testosterone for spermatogenesis. Like most hormones, testosterone is supplied to target tissues in the blood where much of it is transported bound to a specific plasma protein, sex hormone-binding globulin (SHBG).
Homocysteine is an endogenous metabolite involved in methylation processes in the body. Mildly elevated homocysteine appears to be an independent risk factor for both cardiovascular and atherosclerotic disease, where if the 8-10μM normal range is elevated by around 5μM, it is thought to confer 60-80% greater risk of atherosclerotic disease. Although it may not independently cause problems, it may play a causative role in the context of the whole body system, since it is atherogenic by augmenting LDL oxidation and promoting conversion of macrophages into foam cells.
How to maximize its effects: Take 20 grams of whey protein powder in the 30 minutes before working out, and take 40 grams within 60 minutes after training. Also consider taking 20-40 grams of whey immediately upon waking every morning to kick-start muscle growth. Your best bet is to choose a whey powder that contains whey protein hydrolysates (whey protein broken down into smaller fragments for faster digestion) or whey protein isolate.
A proper warm-up is an important part of an effective strength workout. Start by foam rolling your muscles to wake 'em up. "Foam rolling loosens up tight muscles so that they work the way they're designed to," says Davis. A dynamic warm-up is another important part of your pre-workout routine, it preps your muscles for the work they're about to do and helps increase your range of motion. Increasing your range of motion allows you to go deeper into those squats and fully extend those bicep curls, which means more muscle recruitment and better results. "These two combined reduce your risk of injury and allow you to push harder during your workout," says Davis. Get started with this five-minute warm-up.
To combat steroid use and in the hopes of becoming a member of the IOC, the IFBB introduced doping tests for both steroids and other banned substances. Although doping tests occurred, the majority of professional bodybuilders still used anabolic steroids for competition. During the 1970s, the use of anabolic steroids was openly discussed, partly due to the fact they were legal. In the Anabolic Steroid Control Act of 1990, U.S. Congress placed anabolic steroids into Schedule III of the Controlled Substances Act (CSA). In Canada, steroids are listed under Schedule IV of the Controlled Drugs and Substances Act, enacted by the federal Parliament in 1996.
As mentioned earlier, supplementation of creatine in youth has been noted to improve the swim bench test (a thirty second sprint followed by another after a five minute break). One study noted improvement when examining a 400 meter test after 10g of creatine was taken over seven days with some orange juice. The improvement was mostly attributable to increased performance on the last 50m stretch.
Now, creatine combines with inorganic phosphate to form phosphocreatine in a reaction accelerated by an enzyme named creatine kinase. Most of us increase our phosphocreatine stores when we consume creatine. In turn, our fortified phosphocreatine stores can donate additional high-energy phosphate groups during very energy-demanding activities, more efficiently recycling ATP from ADP. This is the main way creatine supplementation improves high-intensity exercise performance.
For example, a 2015 review published in the peer-reviewed journal Applied Physiology, Nutrition, and Metabolism suggests that, for maximal muscle growth, people consume 25 to 35 grams of protein at breakfast, lunch and dinner. You'll find that amount of protein in a chicken breast, a cup of Greek yogurt with slivered almonds or about a three-quarter block of tofu.
Taking creatine can also cause 5-10 lbs of water-weight gain. The stress from extra water causes muscle cells to grow faster. This is one reason why creatine supplementation increases muscle growth over the long term. Novice weightlifters see more benefits with creatine than seasoned athletes, since they have more muscle to gain. (That doesn’t mean athletes shouldn’t take creatine though.)