Women who train hard and reach low body fat levels, say under 10 percent, may be at risk of losing their periods as a result of hormonal disruption to estrogen production. Exercise-induced estrogen declines can result in bone loss in a way similar to that which occurs at the menopause. Loss of periods from athletic training is not uncommon but does require that you see a doctor, or better still, a sports physician and sports nutritionist to assess what is required to address the problem. Calcium supplements may be a part of the solution if bone health is likely to be affected. 
While many of the claims are based on scientifically based physiological or biochemical processes, their use in bodybuilding parlance is often heavily colored by bodybuilding lore and industry marketing and as such may deviate considerably from traditional scientific usages of the terms. In addition, ingredients listed have been found at times to be different from the contents. In 2015, Consumer Reports reported unsafe levels of arsenic, cadmium, lead and mercury in several of the protein powders that were tested.[7]
Second, strength training has a much greater level of excess post-exercise oxygen consumption than aerobic exercise.  What does this mean?  When you finish a workout, your body needs to do a lot of work to replenish itself in order to bring itself back to a normal state (the way it was before you worked out).  This takes a lot of energy, and some studies have shown that it can boost your metabolism for up to 38 hours after you finish your workout.
Key point: Past a certain number of sets, the marginal increases in protein synthesis NO LONGER outweigh the cost of doing more sets. If 8 sets of chest exercises produce 95% of possible muscle protein synthesis… then it makes very little sense to do ANOTHER 10 sets (like most chest workouts) to try and inch out the final 5% of stimulation. Those extra 10 sets are simply damaging your muscle unnecessarily and impairing your ability to recover.
Spillane M, Schoch R, Cooke M, Harvey T, Greenwood M, Kreider R, Willoughby DS. The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels. J Int Soc Sports Nutr. 2009;6:6. doi: 10.1186/1550-2783-6-6. [PMC free article] [PubMed] [CrossRef]
Deldicque et al [32] found a 250%, 45% and 70% increase for collagen mRNA, glucose transporter 4 (GLUT4) and Myosin heavy chain IIA, respectively after 5 days creatine loading protocol (21 g/d). The authors speculated that creatine in addition to a single bout of resistance training can favor an anabolic environment by inducing changes in gene expression after only 5 days of supplementation.
Whey protein contains high levels of all the essential amino acids and branched-chain amino acids. It also has the highest content of the amino acid cysteine, which aids in the biosynthesis of glutathione. For bodybuilders, whey protein provides amino acids used to aid in muscle recovery.[27] Whey protein is derived from the process of making cheese from milk. There are three types of whey protein: whey concentrate, whey isolate, and whey hydrolysate. Whey concentrate is 29–89% protein by weight whereas whey isolate is 90%+ protein by weight. Whey hydrolysate is enzymatically predigested and therefore has the highest rate of digestion of all protein types.[27]
I was building up, bulking, going after the mass, which to me meant 230 pounds of sheer body weight. At that time, I didn’t care about my waist or anything else that would give me a symmetrical look. I just wanted to build a gigantic 250-pound body by handling a lot of weight and blasting my muscles. My mind was into looking huge, into being awesome and powerful. I saw it working. My muscles began bursting out all over. And I knew I was on my way.”
Safety. Iron overload may cause a disease called hemochromatosis in some susceptible people. Iron supplements should only be prescribed by a doctor, and for athletes or those who train heavily, a sports physician combined with a sports dietitian may be preferable. Be sure to take care with this because iron supplements should not be taken casually. Iron supplements may cause constipation and gastric upset in some people.
Supplementation of creatine at 20g daily for a loading phase, followed by 10g daily for eight weeks in healthy volunteers resulted in a 23% reduction of triglycerides, which remained lower than baseline for four weeks after supplementation ceased, [321] while vLDL (the lipid particle which carries most of the triglyerides. which TMG causes to be released from the liver) was also reduced by 22% in this study.[321] 

Heart Failure is one of the single most common complications that face many people today. When a heart ages, the cells collect a yellow-brown layer which is waste and can lead to heart complications. This process is known as lipofuscin, or “aging pigment” which leads to death opposed to someone who can delay that as far as possible. [3] In mice, a study was performed where two groups of mice who had lipofuscin underwent different experiments, one group received creatine supplementation, and one group did not receive supplementation. What they found was that the mice who supplemented creatine lived 9% longer than the ones who did not receive creatine. 9% translated into human years results in almost 7 years, which could suggest that if you suffer from this deterioration, creatine supplementation could potentially increase your longevity by 7 years. [3]
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Creatine is classified as a "dietary supplement" under the 1994 Dietary Supplement Health and Education Act and is available without a prescription. Creatine is not subjected to FDA testing, and the purity and hygienic condition of commercial creatine products may be questionable [21]. A 1998 FDA report lists 32 adverse creatine-associated events that had been reported to FDA. These include seizure, vomiting, diarrhea, anxiety, myopathy, cardiac arrhythmia, deep vein thromboses and death. However, there is no certainty that a reported adverse event can be attributed to a particular product [22]. A recent survey of 28 male baseball players and 24 male football players, ages 18 to 23, found that 16 (31%) experienced diarrhea, 13 (25%) experienced muscle cramps, 7 (13%) reported unwanted weight gain, 7 (13%) reported dehydration, and 12 reported various other adverse effects [23].
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]
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.
The general strategy adopted by most present-day competitive bodybuilders is to make muscle gains for most of the year (known as the "off-season") and, approximately 12–14 weeks from competition, lose a maximum of body fat (referred to as "cutting") while preserving as much muscular mass as possible. The bulking phase entails remaining in a net positive energy balance (calorie surplus). The amount of a surplus in which a person remains is based on the person's goals, as a bigger surplus and longer bulking phase will create more fat tissue. The surplus of calories relative to one's energy balance will ensure that muscles remain in a state of anabolism.
Researchers described the study as one of the first to examine how strength training can reduce the risk of cardiovascular disease, separate from the effects of aerobic activity like running or long walks. The point: for those who are not meeting recommended guidelines for aerobic activity—perhaps because they lack the time—bursts of weight training can be enough.
1. Are you tracking calories? Doesn't have to be religiously but one should have a general idea of where they're at if the goal is mass gain and things have stalled. I'm not talking about weighing every gram of food you put in your mouth and meticulously logging your life on MyFitnessPal. As long as you're aware (within 100-200 calories) of what's going in, you should have an idea of what to adjust.
Jager et al [60] observed 1.17 and 1.29 greater peak plasma creatine concentration 1 hour after ingesting creatine pyruvate compared to isomolar amount of CM and creatine citrate respectively. However time to peak concentration, and velocity constants of absorption and elimination, was the same for all three forms of creatine. Although not measured in this study it is questionable that these small differences in plasma creatine concentrations would have any effect on the increase of muscle creatine uptake. Jäger et al [61] investigated the effects of 28-days of creatine pyruvate and citrate supplementation on endurance capacity and power measured during an intermittent handgrip (15 s effort per 45s rest) exercise in healthy young athletes. The authors used a daily dose protocol with the intention to slowly saturate muscle creatine stores. Both forms of creatine showed slightly different effects on plasma creatine absorption and kinetics. The two creatine salts significantly increased mean power but only pyruvate forms showed significant effects for increasing force and attenuating fatigability during all intervals. These effects can be attributed to an enhanced contraction and relaxation velocity as well as a higher blood flow and muscle oxygen uptake. On the other hand, the power performance measured with the citrate forms decreases with time and improvements were not significant during the later intervals. In spite of these positive trends further research is required about the effects of these forms of creatine as there is little or no evidence for their safety and efficacy. Furthermore the regularity status of the novel forms of creatine vary from country to country and are often found to be unclear when compared to that of CM [62].
Product reviews – Since the effectiveness of products varies based on a wide number of factors, one of the best things to do is read creatine product reviews. The best rated creatine products will have consistently good reviews, meaning a lot of people use that product and would recommend it. However – remember to take reviews with a grain of salt, as there’s a lot of ignorance and misinformation out there.
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.

Studies have deemed staying in the range of 3 to 5 g per day range for maintenance to be safe, and while higher levels have been tested under acute conditions without adverse effects, there isn’t sufficient evidence to determine long-term safety. (8) If you’re interested in upping your creatine consumption, you should work with your doctor or dietitian to make sure it's right for your goals and health history.
Before getting into the nitty-gritty details about supplements, it’s important to have a good understanding of how muscle growth works. When you take a muscle growth supplement, the role it plays in helping you reach your goals should be very clear. With the supplements available on the market, you can be sure that while some serve an important purpose, others are gimmicks. It’s easier to identify the money wasters if you know how muscle building works.

A: The literature supports roughly 0.8-1 gram per pound of bodyweight in young adults. Can you eat more? As long as you have healthy, functioning kidneys, yes. Will you receive any further physiological benefit from it? Most likely, no. Not only that, since our calories are set, if we choose to overconsume protein then we must reduce either carbohydrates and/or fat in order to keep caloric expenditure within our set range. Once protein needs are met (~0.8-1g/lb of bodyweight) you will likely see greater benefits from higher carbohydrate consumptions given the influence they have on anabolism and the anaerobic energy pathway. However, as I mentioned above, these recommendations will differ for older trainees given the blunted anabolic response from the ingestion of amino acids. 

Still, any supplement should be used carefully and after discussion with a dietitian or doctor. There are some potential health risks and side effects that you should be aware of before taking creatine. Muscle cramping, nausea, diarrhea, dizziness, gastrointestinal pain, dehydration, weight gain, water retention, heat intolerance, and fever have all been linked to the supplement. (13)
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).[398] 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.[405]
A great analogy that I like is that the balance between training and recovery is like digging a hole. Each time you lift, you dig yourself deeper and make it harder to climb out of the hole. To get back out again, you have to fill in the hole to return to ground level, and the only way to fill it is with food and rest. If you overdo it in the gym by pushing too hard, you won’t be able to train as often or at a high capacity. Eventually, you’ll get injured.
^ Jump up to: a b c Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM (2017). "A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults". Br J Sports Med. 52 (6): bjsports–2017–097608. doi:10.1136/bjsports-2017-097608. PMC 5867436. PMID 28698222.
Muscle imbalances are quite common among strength athletes and are arguably the most common cause of their injuries. Many times this is due to a “weak link” in the kinetic chain of muscles that activate during their activity. Identifying the “weak” muscle and being able to feel, isolate and contract that “weak” muscle makes correctional exercise and rehab much easier. Bodybuilding training, with its focus on “feel” rather than movement, helps to train and develop the mind to muscle connection. This comes in handy when you need to train a muscle imbalance with correctional exercise and, in the case of injury, for rehab.

When looking for a whey protein powder to purchase, seek out powders that offer at least 20 g of protein per serving (one scoop) and are low in carbohydrates (aim for 5 g per serving or less). You may run into whey protein isolate, which looks attractive because it’s a higher concentration of protein. However, avoid this one as in the extreme processing, proteins are denatured that can render them less effective. In addition, these formulas are also often chock full of artificial sweeteners. Instead, look for powders from grass-fed cows that aren’t pumped with hormones.
In otherwise healthy adults subject to leg immobilization for two weeks while taking 20g creatine daily during immobilization and then 5g daily during eight weeks of rehabilitation, it was noted that the creatine group failed to reduce atrophy during the immobilization (10% reduction in cross sectional area and 22-25% reduction in force output) despite preventing a decrease in phosphocreatine, yet experienced a significantly enhanced rate of regrowth and power recovery.[358] A similarly structured and dosed study has also noted greater expression of skeletal muscle, GLUT4 expression, and a 12% increase in muscle phosphocreatine content.[330]
Side-Effects: While the signs of a great body may make one think that there cannot be anything wrong with bodybuilding supplements, the facts speak otherwise. Bodybuilding supplements do have side-effects and you must listen to your trainer before giving in to the thoughts of buying one. Creatine can cause heart problems, kidney problems, dehydration, diarrhoea and muscle cramping. You must also discuss your medical history with the trainer. 
It’s not just about lifting—it’s about lifting safely and correctly. And if you’re not performing exercises properly, it’s impossible to make any progress. “When someone is just starting to work out, it can help to work closely with a knowledgeable personal trainer in order to learn proper form,” says Ingram. But that goes for experienced lifters, too. If you aren’t sure about a movement, it’s better to ask. “If you’re not working the correct muscles, you can’t expect them to grow,” explains Ingram. 

Creatine ingested through supplementation is transported into the cells exclusively by CreaT1. However, there is another creatine transporter Crea T2, which is primarily active and present in the testes [12]. Creatine uptake is regulated by various mechanisms, namely phosphorylation and glycosylation as well as extracellular and intracellular levels of creatine. Crea T1 has shown to be highly sensitive to the extracellular and intracellular levels being specifically activated when total creatine content inside the cell decreases [12]. It has also been observed that in addition to cytosolic creatine, the existence of a mitochondrial isoform of Crea T1 allows creatine to be transported into the mitochondria. Indicating another intra-mitochondrial pool of creatine, which seems to play an essential role in the phosphate-transport system from the mitochondria to the cytosol [13]. Myopathy patients have demonstrated reduced levels of total creatine and phosphocreatine as well as lower levels of CreaT1 protein, which is thought to be a major contributor to these decreased levels [14].
What kind of exercises? Work all major muscle groups, starting with the larger muscles. Always include exercises for opposing muscles: for example, work the biceps and triceps of your arms, and the quadriceps and hamstrings of your thighs. Avoid above-the-shoulder exercises if you have arthritis in your upper body, and talk to your doctor before using leg press machines if you have arthritis in your knees or hips.

In humans, studies that investigate links between serotonin and creatine supplementation find that 21 trained males, given creatine via 22.8g creatine monohydrate (20g creatine equivalent) with 35g glucose, relative to a placebo of 160g glucose, was found to reduce the perception of fatigue in hot endurance training, possibly secondary to serotonergic modulation, specifically attentuating the increase of serotonin seen with exercise (normally seen to hinder exercise capacity in the heat[233]) while possibly increasing dopaminergic activity (conversely seen to benefit activity in the heat[234]).[155]
So, one way to make the soreness go away, at least temporarily, is to continue exercising.  This increases blood flow to the muscles and helps them heal.  However, remember that we still need them to heal. So if you’re sore from heavy squats, don’t turn around and do heavy squats again. Try doing squats with no weight or yoga/stretching to help bring the soreness down.
Another category of muscle-building supplements that lifters and bodybuilders use to improve their results are branched-chained amino acids (BCAAs), or BCAAs. Of the 20 amino acids that make up protein, just three are referred to as BCAAs: leucine, isoleucine, and valine. These are the specific amino acids that have been shown to stimulate protein synthesis and help regulate protein metabolism.
Syndromes caused by problems metabolizing creatine. Some people have a disorder that prevents their body from making creatine. This can lead to low levels of creatine in the brain. Low levels of creatine in the brain can lead to decreased mental function, seizures, autism, and movement problems. Taking creating by mouth daily for up to 3 years can increase creatine levels in the brain in children and young adults with a disorder of creatine production called guanidinoacetate methyltransferase (GAMT) deficiency. This can help improve movement and reduce seizures. But it doesn't improve mental ability. Arginine-glycine amidinotransferase (AGAT) deficiency is another disorder that prevents the body from making creatine. In children with this condition, taking creatine for up to 8 years seems to improve attention, language, and mental performance. But taking creatine does not seem to improve brain creatine levels, movement, or mental function in children who have a disorder in which creatine isn't transported properly.
Free weights include dumbbells, barbells, medicine balls, sandbells, and kettlebells. Unlike weight machines, they do not constrain users to specific, fixed movements, and therefore require more effort from the individual's stabilizer muscles. It is often argued that free weight exercises are superior for precisely this reason. For example, they are recommended for golf players, since golf is a unilateral exercise that can break body balances, requiring exercises to keep the balance in muscles.[27]
Product reviews – Since the effectiveness of products varies based on a wide number of factors, one of the best things to do is read creatine product reviews. The best rated creatine products will have consistently good reviews, meaning a lot of people use that product and would recommend it. However – remember to take reviews with a grain of salt, as there’s a lot of ignorance and misinformation out there.
Unfortunately, some people are intolerant to milk, due to the casein (one of the proteins in dairy) and have trouble digesting the sugar in milk, called lactose. If this is the case, stick to whey-only protein shakes. Maximuscle uses Biomax Whey True Protein - a unique blend of whey proteins including whey protein concentrate, isolate and hydrolysate, which are lower in lactose. Biomax Whey True Protein is used in a number of Maximuscle products (Promax and Cyclone).

GLUTs are vesicle transporters that are the rate-limiting steps for bringing glucose into a cell, and GLUT4 is the most active variant.[327] Agents that reduce blood glucose (insulin or AMPK) are known to act via mobilizing GLUT4, and increased GLUT4 expression and activity is indicative of a greater ability to bring glucose into a cell, while reducing it impairs glucose uptake.[328] Rat studies have confirmed that creatine feeding increases muscular GLUT4 expression associated with increased insulin-stimulated glucose uptake.[329]

In muscle cells, the creatine transporter is predominantly localized to the sarcolemmal membrane. Western blot analysis of creatine transporter expression revealed the presence of two distinc protein bands, migrating at 55kDa and 70kDa on reducing SDS-PAGE gels.[147][148] The 73kDa band has been reported to be the predominant band in humans, with no differences based on gender.[148] A more recent report demonstrated that the 55kDa creatine transporter variant is glycosylated, forming the 73 kDa protein. Therefore, the 55 and 75kDa protein bands are actually immature and mature/processed forms of the creatine transporter protein, respectively.[149]

In the stomach, creatine can degrade by about 13% due to the digestive hormone pepsin, as assessed by simulated digestion.[127] Although creatinine is a known byproduct of creatine degradation, simulated gastric digestion did not increase creatinine levels, indicating that other breakdown products were formed. However, creatinine was noted to increase in the presence of pancreatin, a mixture of pancreatic enzymes.[127] 
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.
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.
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]