The creatine transporter is a sodium[139][140] and chloride[141][142] dependent membrane-associated transporter that belongs to the Na+/Cl-dependent family of neurotransmitter transporters.[143] In muscle cells and most other cell types,[131][141] the isomer of the creatine transporter is known as SLC6A8 (solute carrier family 6, member 8). SLC6A8 is encoded by the gene present on the Xq28 region of the human X-chromosome and is expressed in most tissues.[144] A related gene encoding a creatine transporter variant has also been identified at 16p11.1 that is expressed exclusively in the testes.[145] These two transporters share 98% homology.[144][145]
One pilot study using 150mg/kg creatine monohydrate for a five day loading phase followed by maintenance (60mg/kg) for the remainder of the five weeks noted that supplementation was associated with fewer muscle symptoms and complaints alongside improved muscular function,[572] yet a later trial trying to replicate the obsevations using 150mg/kg daily for five weeks noted the opposite, that creatine supplementation exacerbated symptoms.[573] 
^ Jump up to: a b c d Brosnan JT, da Silva RP, Brosnan ME (May 2011). "The metabolic burden of creatine synthesis". Amino Acids. 40 (5): 1325–31. doi:10.1007/s00726-011-0853-y. PMID 21387089. Creatinine loss averages approximately 2 g (14.6 mmol) for 70 kg males in the 20- to 39-year age group. ... Table 1 Comparison of rates of creatine synthesis in young adults with dietary intakes of the three precursor amino acids and with the whole body transmethylation flux
The incidence of liver damage from herbal and dietary supplements is about 16–20% of all supplement products causing injury, with the occurrence growing globally over the early 21st century.[2] The most common liver injuries from weight loss and bodybuilding supplements involve hepatocellular damage with resulting jaundice, and the most common supplement ingredients attributed to these injuries are catechins from green tea, anabolic steroids, and the herbal extract, aegeline.[2]
The winner of the annual IFBB Mr. Olympia contest is generally recognized as the world's top male professional bodybuilder. The winner of the Women's Physique portion of the competition is widely regarded as the world's top female professional bodybuilder. The title is currently held by Juliana Malacarne, who has won every year since 2014. Since 1950, the NABBA Universe Championships have been considered the top amateur bodybuilding contests, with notable winners such as Reg Park, Lee Priest, Steve Reeves, and Arnold Schwarzenegger. Winners generally go on to become professional athletes.

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. 

One case study exists of a man with focal segmental glomerulosclerosis who experienced an accelerated rate of GFR decline during supplementation (5g thrice daily for loading, then a 2g maintenance for seven weeks) which was partially reversed upon supplement cessation. This was deemed strong circumstantial evidence, and the brand of supplement was not named.[616] Elsewhere, interstitial nephritis associated with creatine supplementation has been reported in a man, although symptoms arose four weeks after supplementation started with no evidence to support correlation.[617] Some studies involving athletes and various dietary supplements have attempted to draw a correlation with creatine and cases of rhabdomyolysis.[618][619][620][621] Finally, one study in a diabetic person ingesting both metformin and creatine resulting in metabolic acidosis has attempted to place causation on creatine, but it did not establish causation or circumstantial evidence.[622]
Kidney damage (from anything) will cause high levels of creatinine in blood, and creatine can also increase blood creatinine levels in a manner that is not due to damaging the kidneys. This results in a false positive when trying to diagnose kidney damange when the subject also supplements creatine, and does not signify any actual damage to the kidneys.
After supplementation of creatine monohydrate (loading phase, followed by 19 weeks maintenance), creatine precursors are decreased by up to 50% (loading) or 30% (maintenance), which suggests a decrease in endogenous creatine synthesis during supplementation.[38] This appears to occur through creatine’s own positive feedback and suppression of the l-arginine:glycine amidinotransferase enzyme, the rate-limiting step in creatine synthesis, as levels of intermediates before this stage are typically elevated by up to 75%.[38]
Warm up sets are also important. For example, the same lifter working on his chest would also be advised to complete at least two warm up sets prior to hitting his "core tonnage." Core tonnage refers to the heavier lifts that actually strain your muscles. For example, if the lifter's main sets were at 205 lbs, 225 lbs and 235 lbs on the bench, then a warmup of 5 reps of 135 and 5 reps of 185 would be advisable. Some lifters will warm up with a 50/50 set for example 50% of the target weight for 50% of the target repetitions. When properly warmed up the lifter will then have more strength and stamina since the blood has begun to flow to the muscle groups.[7]

Retinol (Vitamin A) B vitamins: Thiamine (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5) Pyridoxine (B6) Biotin (B7) Folic acid (B9) Cyanocobalamin (B12) Ascorbic acid (Vitamin C) Ergocalciferol and Cholecalciferol (Vitamin D) Tocopherol (Vitamin E) Naphthoquinone (Vitamin K) Calcium Choline Chromium Cobalt Copper Fluorine Iodine Iron Magnesium Manganese Molybdenum Phosphorus Potassium Selenium Sodium Sulfur Zinc


^ Jump up to: a b c d e f g h Momaya A, Fawal M, Estes R (April 2015). "Performance-enhancing substances in sports: a review of the literature". Sports Med. 45 (4): 517–531. doi:10.1007/s40279-015-0308-9. PMID 25663250. Wilson et al. [91] demonstrated that when non-resistance trained males received HMB pre-exercise, the rise of lactate dehydrogenase (LDH) levels reduced, and HMB tended to decrease soreness. Knitter et al. [92] showed a decrease in LDH and creatine phosphokinase (CPK), a byproduct of muscle breakdown, by HMB after a prolonged run. ... The utility of HMB does seem to be affected by timing of intake prior to workouts and dosage [97].
Electrolytes derive mainly from minerals in the diet and they maintain fluid balance and assist the nervous system to perform muscle contractions. Electrolytes are sodium, potassium, magnesium, calcium and chloride, bicarbonate, phosphate, sulfate. Exercisers are particularly dependent on sodium and potassium balance. Carbohydrates are important for fueling exercise, including vigorous weight training, and in post-exercise energy replacement nutrition. Carbohydrates, mostly sugars, are formulated in sports drinks with electrolytes such as sodium chloride and potassium and sometimes magnesium.
Due to the growing concerns of the high cost, health consequences, and illegal nature of some steroids, many organizations have formed in response and have deemed themselves "natural" bodybuilding competitions. In addition to the concerns noted, many promoters of bodybuilding have sought to shed the "freakish" perception that the general public has of bodybuilding and have successfully introduced a more mainstream audience to the sport of bodybuilding by including competitors whose physiques appear much more attainable and realistic.
Parashos, S. A., Swearingen, C. J., Biglan, K. M., Bodis-Wollner, I., Liang, G. S., Ross, G. W., Tilley, B. C., and Shulman, L. M. Determinants of the timing of symptomatic treatment in early Parkinson disease: The National Institutes of Health Exploratory Trials in Parkinson Disease (NET-PD) Experience. Arch Neurol. 2009;66:1099-1104. View abstract.

A meta-analysis of 16 studies conducted on creatine and its influence on power and strength,[368][369] (with or without exercise in all age groups above 16, but placebo controlled and without crossover[368]) compiled studies utilizing a 5-7 day loading period with continued maintenance thereafter and studies assessing 1-3 rep bench press strength in trained young men. Seven studies (four of which are online[370][371][372][373]) totaling 70 people using creatine and 73 people in placebo showed a 6.85kg increase in strength relative to placebo, the benefits of which peaked at 8 weeks.[368] This meta-analysis also quantified a significant increase in squat strength (9.76kg) yet failed to find a significant influence on peak bicep contraction power, which may have been influenced by the two null studies[374][375] being in elderly people while the positive study[376] was statistically outweighed, but noted an 1.8-fold increase in power associated with creatine over placebo. The other meta-analysis conducted the following year[369] calculated effect sizes for creatine supplementation and noted no significant differences between genders or when comparing trained and untrained individuals. The mean effect size of exercises lasting below 30s (those that use the creatine-phosphate system) was 0.24+/-0.02 and performed significantly better than placebo, where exercise increased performance by 4.2+/-0.6% while the addition of creatine enhanced this effect to 7.5+/-0.7%.[369]
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.
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.
While this nonessential amino acid may not deliver earth-shattering PRs or extreme muscle growth, it does play an important role in repair and recovery. Glutamine works by removing excess ammonia, which can accumulate during intense exercise, helping to regulate your body's acid-base balance. Individuals who are engaged in heavy resistance training, two-a-day training splits, or are in a calorie deficit may benefit from the extra support of glutamine supplementation.
Another study demonstrated that females receiving 4 days of high-dose creatine intake (20 g/day) followed by low-dose creatine intake (5 g/day) during 10 weeks of resistance training (3hours/week) increased muscle PCr concentrations by 6%. Also, maximal strength of the muscle groups trained increased by 20-25%, maximal intermittent exercise capacity of the arm flexors increased by 10-25% and fat-free mass increased by 60% [11].
Carducci, C., Birarelli, M., Leuzzi, V., Carducci, C., Battini, R., Cioni, G., and Antonozzi, I. Guanidinoacetate and creatine plus creatinine assessment in physiologic fluids: an effective diagnostic tool for the biochemical diagnosis of arginine:glycine amidinotransferase and guanidinoacetate methyltransferase deficiencies. Clin Chem 2002;48:1772-1778. View abstract.
In fact, in one new study comparing the effects of aerobic exercise versus resistance training on the psychological health of obese adolescents, researchers found that people in the resistance group experienced significantly greater self-esteem and perceived strength over four weeks. But what’s most interesting is that the feeling of getting stronger — rather than any measurable gains — was all it took to give them a boost.

Finally, starvation (nutrient deprivation for four days) appears to increase activity of the creatine transporter secondary to decreasing serine phosphorylation (SGK target)[173] with no influence on tyrosine phosphorylation (c-Src target).[173] Starvation-induced increases in creatine influx do not necessarily mean more phosphocreatine, however, due to a depleted cellular energy state.[173]
There have been a few reported renal health disorders associated with creatine supplementation [73,74]. These are isolated reports in which recommended dosages are not followed or there is a history of previous health complaints, such as renal disease or those taking nephrotoxic medication aggravated by creatine supplementation [73]. Specific studies into creatine supplementation, renal function and/or safety conclude that although creatine does slightly raise creatinine levels there is no progressive effect to cause negative consequences to renal function and health in already healthy individuals when proper dosage recommendations are followed [73-77]. Urinary methylamine and formaldehyde have been shown to increase due to creatine supplementation of 20 g/d; this however did not bring the production outside of normal healthy range and did not impact on kidney function [56,78]. It has been advised that further research be carried out into the effects of creatine supplementation and health in the elderly and adolescent [73,75]. More recently, a randomized, double blind, 6 month resistance exercise and supplementation intervention [79] was performed on elderly men and women (age >65 years) in which subjects were assigned to either a supplement or placebo group. The supplement group was given 5 g CM, 2 g dextrose and 6 g conjugated linoleic acid/d, whilst the placebo group consumed 7 g dextrose and 6 g safflower oil/d. CM administration showed significantly greater effects to improve muscular endurance, isokinetic knee extension strength, fat free mass and to reduce fat mass compared to placebo. Furthermore the supplement group had an increase in serum creatinine but not creatinine clearance suggesting no negative effect on renal function.
The exercises that allow you to use the greatest amount of weight are the ones that help you build muscle the fastest. These also happen to be the lifts that allow for the greatest percentage of increases in loading. We’re talking compound (multi-joint) exercises here, done with free weights. You’re not going to grow at nearly the same rate with a workout comprising machine exercises and isolation movements.
Beach muscles and Olympic lifts draw more attention. But the many little stabilizer muscles around your shoulders, hips, and midsection — collectively the core — provide a strong foundation. Challenging the stability and mobility of these key muscles with medicine balls, physioballs, mini-bands, and rotational movements (lifting, chopping) pays huge dividends.
Because so many product labels list scientific references to back up the manufacturers' claims of performance and efficacy, or effectiveness, it's important to understand what constitutes a solid scientific study. A single study, even an optimally designed one, isn't considered scientific proof. The results have to be replicated several times before they're officially accepted as fact.
Beginners are advised to build up slowly to a weight training program. Untrained individuals may have some muscles that are comparatively stronger than others; nevertheless, an injury can result if (in a particular exercise) the primary muscle is stronger than its stabilizing muscles. Building up slowly allows muscles time to develop appropriate strengths relative to each other. This can also help to minimize delayed onset muscle soreness. A sudden start to an intense program can cause significant muscular soreness. Unexercised muscles contain cross-linkages that are torn during intense exercise. A regimen of flexibility exercises should be implemented before weight training begins, to help avoid soft tissue pain and injuries.
According to the abstract, in the stratified analyses by forms of aerobic exercise, weekly resistance exercise of 1 time or 1-59 minutes was associated with lower risks of total cardiovascular events and cardiovascular disease, regardless of meeting the aerobic exercise guidelines. The analysis showed that resistance training reduced the risk of cardiovascular events in 2 ways: training had a direct association with cardiovascular risk, and resistance training indirectly lowered cardiovascular risk by decreasing body mass index.
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