In the modern bodybuilding industry, the term "professional" generally means a bodybuilder who has won qualifying competitions as an amateur and has earned a "pro card" from their respective organization. Professionals earn the right to compete in competitions that include monetary prizes. A pro card also prohibits the athlete from competing in federations other than the one from which they have received the pro card.[12] Depending on the level of success, these bodybuilders may receive monetary compensation from sponsors, much like athletes in other sports.
Three additional studies suggest that creatine supplementation may not be beneficial for running velocity, sprint swimming performance, or a maximal cycling effort [7]. Short bouts of repeated anaerobic activity have shown some potential benefits with creatine supplementation use in a laboratory setting. However, creatine supplementation has not been shown to enhance single-event performance such as stationary cycling [16-19]. Taken together, these studies do not support creatine supplementation to enhance aerobic activities such as distance running.
Creatine is known to occur in highly concetrated levels in chicken photoreceptors, relative to other parts of the eye (10-15mM[466]) alongside high levels of creatine kinase.[466] The creatine transporter in human eyes also seems to be concentrated in the photoreceptors,[468] which are known to be susceptible to hypoxic cellular death[471][472] which, for humans, usually means retinal detachment.[473]

It is prudent to note that creatine supplementation has been shown to reduce the body’s endogenous production of creatine, however levels return to normal after a brief period of time when supplementation ceases [1,6]. Despite this creatine supplementation has not been studied/supplemented with for a relatively long period. Due to this, long term effects are unknown, therefore safety cannot be guaranteed. Whilst the long term effects of creatine supplementation remain unclear, no definitive certainty of either a negative or a positive effect upon the body has been determined for many health professionals and national agencies [19,78]. For example the French Sanitary Agency has banned the buying of creatine due to the unproven allegation that a potential effect of creatine supplementation could be that of mutagenicity and carcinogenicity from the production of heterocyclic amines [78]. Long term and epidemiological data should continue to be produced and collected to determine the safety of creatine in all healthy individuals under all conditions [78].
This suppression of creatine synthesis is thought to actually be beneficial, since creatine synthesis requires s-adenosyl methionine as a cofactor and may use up to 40-50% of SAMe for methylation[35][36][122] (initially thought to be above 70%, but this has since been re-evaluated[122]) though the expected preservation of SAMe may not occur with supplementation.[487] Reduced creatine synthesis, via preserving methyl groups and trimethylglycine (which would normally be used up to synthesize SAMe), is also thought to suppress homocysteine levels in serum,[37] but this may also not occur to a practical level following supplementation.[487]
Without supplementation, creatine is formed primarily in the liver, with minor contributions from the pancreas and kidneys. The two amino acids, glycine and arginine, combine via the enzyme Arginine:Glycine amidinotransferase (AGAT) to form ornithine and guanidoacetate. This is the first of two steps in creatine synthesis, and although rare, any deficiency of this enzyme can result in mild mental retardation and muscular weakness.[28] AGAT is also the primary regulatory step, and an excess of dietary creatine can suppress activity of AGAT to reduce creatine synthesis[29] by reducing AGAT mRNA levels, rather than resulting in competitive inhibition.[30]
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] 

Cancel, pause, or adjust your order at any time, hassle free. Your credit card will only be charged when your order ships. The discount applied every time is 15% off. Since it would be weird to subscribe to a kettlebell, the subscriptions and subscription discounts are only for things you'll need often, like supplements, foods, and personal care items.
An upper/lower split can last you forever. A lot of massive, strong powerlifters stick with that throughout their entire lifting careers. However, if you’re older and/or have some trouble recovering, you may prefer a push/pull/legs split that has you training everything directly once per week. This is how most famous bodybuilders have trained in the past and many still do.
What you eat plays a big role in how much muscle your body can build. Proteins are especially important for building muscle. When you eat protein, your body breaks it down into amino acids which are the building blocks of muscle. How much protein you should include in your diet depends on a number of factors including your age and muscle building goals. Older adults who engage in resistance training and those hoping for maximum muscle growth should eat 1 to 1.3 grams of protein per kg of body weight (2, 3). If you weigh 150 lbs, that means you should take between 68 and 88 g of protein daily. Other recommendations are more modest, suggesting that .36 grams of protein per pound of body weight is enough.

If you're a beginner, just about any workout will be intense enough to increase protein synthesis. But if you've been lifting for a while, you'll build the most muscle quickest if you focus on the large muscle groups, like the chest, back, and legs. Add compound lifts like squats, deadlifts, pullups, bent-over rows, bench presses, dips, and military presses to your workout to work them the most efficiently.

Beta-alanine is a naturally occurring non-essential amino acid that comes into the body through foods that are rich in protein. The performance-enhancing aspect of beta-alanine (BA) is due to its ability to increase intra-muscular levels of carnosine. Increasing beta-alanine through supplementation may raise carnosine levels by over 60 percent in as quickly as four weeks.[6]
It is known that intracellular energy depletion (assessed by a depletion of ATP) stimulates AMPK activity in order to normalize the AMP:ATP ratio,[333][334] and when activated AMPK (active in states of low cellular energy[335] and colocalizes with creatine kinase in muscle tissue[336]) appears to inhibit creatine kinase via phosphorylation (preserving phosphocreatine stores but attenuating the rate that creatine buffers ATP). While phosphocreatine technically inhibits AMPK, this does not occur in the presence of creatine at a 2:1 ratio.[334] It seems that if the ratio of phosphocreatine:creatine increases (indicative of excess cellular energy status) that AMPK activity is then attenuated, since when a cell is in a high energy status, there is less AMP to directly activate AMPK.[334][336][337]