The majority of creatine in the human body is in two forms, either the phosphorylated form making up 60% of the stores or in the free form which makes up 40% of the stores. The average 70 kg young male has a creatine pool of around 120-140 g which varies between individuals [10,11] depending on the skeletal muscle fiber type [1] and quantity of muscle mass [11]. The endogenous production and dietary intake matches the rate of creatinine production from the degradation of phosphocreatine and creatine at 2.6% and 1.1%/d respectively. In general, oral creatine supplementation leads to an increase of creatine levels within the body. Creatine can be cleared from the blood by saturation into various organs and cells or by renal filtration [1].
McArdle’s disease is a myopathic disorder associated with fatigue and contractile dysfunction as a result of alterations in the release of glucose from glycogen (via defects in myophosphorylase enzyme function) resulting in an inability to conduct high intensity work as easily.[548] Creatine is thought to be therapeutic because beyond the general strength enhancing properties of creatine, people with McArdle’s disease have an upregulation of phosphofructokinase (PFK) enzyme activity [570] and increasing phosphocreatine storages suppresses the activity of this enzyme.[571]
Cyclocreatine (1-carboxymethyl-2-iminoimidazolidine) is a synthetic analogue of creatine in a cyclic form. It serves as a substrate for the creatine kinase enzyme system, acting as a creatine mimetic. Cyclocreatine may compete with creatine in the CK enzyme system to transfer phosphate groups to ADP, as coincubation of both can reduce cyclocreatine’s anti-motility effects on some cancer cells.[96]

In weight training, as with most forms of exercise, there is a tendency for the breathing pattern to deepen. This helps to meet increased oxygen requirements. Holding the breath or breathing shallowly is avoided because it may lead to a lack of oxygen, passing out, or an excessive build up of blood pressure. Generally, the recommended breathing technique is to inhale when lowering the weight (the eccentric portion) and exhale when lifting the weight (the concentric portion). However, the reverse, inhaling when lifting and exhaling when lowering, may also be recommended. Some researchers state that there is little difference between the two techniques in terms of their influence on heart rate and blood pressure.[8] It may also be recommended that a weight lifter simply breathes in a manner which feels appropriate.


Despite a possible decreasing creatine content in the muscles when maintenance is deemed suboptimal, the overall retention of weight and lean mass is merely additive over time. This is thought to be due to increases in skeletal muscle production (increase in body weight) compensating for the progressive declines in water and glycogen content (decreases in body weight).
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]

One limitation of many free weight exercises and exercise machines is that the muscle is working maximally against gravity during only a small portion of the lift. Some exercise-specific machines feature an oval cam (first introduced by Nautilus) which varies the resistance, so that the resistance, and the muscle force required, remains constant throughout the full range of motion of the exercise.


JAK2 (Janus-Activating Kinase 2) is a novel protein that has been shown to suppress the activity of the creatine transporter CrT in vitro. The effects of JAK2 on CrT are not well-understood in vivo, however. Given that growth hormone activates both c-src (increases CrT activity) and JAK2- which has been found to decrease CrT activity, it is plausible that JAK2 may function as a negative-feedback regulator of creatine uptake. Future research is needed to better understand the role of JAK2 on CrT activity in vivo.
Having a strong butt will get you far—literally. Our glutes are responsible for powering us through everything from long runs to tough strength workouts to a simple jaunt up a flight of stairs. Strong glutes that can take on the brunt of the work can help us avoid overcompensating with smaller muscles during lower-body exercises. Plus, beyond just helping us move, the glutes play an important role in "stabilizing our entire lumbo-pelvic-hip complex," says Cori Lefkowith, NASM-certified personal trainer and owner of Redefining Strength in Costa Mesa, California. That translates to better form, more efficient movement, and a reduced risk of straining your lower back and hips.
Adequate hydration is essential to muscle building, yet few people get enough water, even without daily exercise. So in addition to the daily 8 to 10 glasses of water recommended by the Dietary Guidelines for Americans, Karas suggests an additional 12 to 16 ounces before working out. He then recommends another 8 to 10 ounces for every 15 minutes of vigorous exercise.
A: First, you have to realize that when one is gaining weight it’s nearly impossible (steroid discussion aside) to gain solely muscle without the acquisition of some body fat as well. That being said though, you can improve thedistribution of lean body mass to fat mass by ensuring that your calorie consumption isn’t too aggressive (i.e. 1000+ over your BMR). Also, it should go without saying, but you need to be training hard while focusing on progressive overload to ensure that the calories you’re ingesting are actually going towards muscle growth. You shouldn’t be neglecting cardiovascular work either; both HIIT and LISS each play a role in enhancing mitochondrial density, balancing neurotransmitters, improving oxidative capacity, and influencing brain plasticity.

By increasing the overall pool of cellular phosphocreatine, creatine supplementation can accelerate the reycling of ADP into ATP. Since ATP stores are rapidly depleted during intense muscular effort, one of the major benefits of creatine supplementation is its ability to regenerate ATP stores faster, which can promote increased strength and power output. Over 95% of creatine is stored in muscle at a maximum cellular concentration of 30uM. Creatine storage capacity is limited, though it increases as muscle mass increases.[24] A 70 kg male with an average physique is assumed to have total creatine stores of approximately 120g.[25] The body can store a lot more energy as glycogen in the liver, brain, and muscles,[26][27] and even more as fat.


Sandow was so successful at flexing and posing his physique that he later created several businesses around his fame, and was among the first to market products branded with his name. He was credited with inventing and selling the first exercise equipment for the masses: machined dumbbells, spring pulleys, and tension bands. Even his image was sold by the thousands in "cabinet cards" and other prints. Sandow was a perfect "Gracilian", a standard of ideal body proportions close to those of ancient Greek and Roman statues. Men's physiques were then judged by how closely they matched these proportions.

Aim to eat roughly 250 to 500 extra calories per day. To make sure that any weight gained is from muscle, Fitzgerald recommends that the bulk of those calories come from protein. In a 2014 Pennington Biomedical Research Center study, people who ate a high-calorie diet rich in protein stored about 45 percent of those calories as muscle, while those following a low-protein diet with the same number of calories stored 95 percent of those calories as fat.
It is suggested [16,37] that another mechanism for the effect of creatine could be enhanced muscle glycogen accumulation and GLUT4 expression, when creatine supplementation is combined with a glycogen depleting exercise. Whereas it has been observed [38] that creatine supplementation alone does not enhance muscle glycogen storage. Hickner et al [15] observed positive effects of creatine supplementation for enhancing initial and maintaining a higher level of muscle glycogen during 2 hours of cycling. In general, it is accepted that glycogen depleting exercises, such as high intensity or long duration exercise should combine high carbohydrate diets with creatine supplementation to achieve heightened muscle glycogen stores [39].
Studies conducted in vegetarians tend to show cognitive enhancement in youth, possibly due to a creatine deficiency, as compared to omnivores.[272][60][61] Vegetarian diets have lower levels of circulating creatine prior to supplementation, but attain similar circulating levels as omnivores when both groups supplement.[272][273] Building on the latter, supplementation of creatine monohydrate in a loading protocol (20g daily in orange juice) in omnivores does not alter levels of creatine in white matter tissue in the brain (test subjects: competitive athletes).[274] In most of the parameters that vegetarians experience benefits, omnivores fail to experience statistically significant benefits[275], except possibly when sleep deprived, where the cognitive improvements rival that seen in vegetarians.[276] Elderly people who are omnivorous may also experience increases in cognition to a similar level, in regard to long-term memory as well as forward number and spatial recall, although the study in question failed to find any significant benefit on backward recall or random number generation,[38] the latter of which is a test for executive working memory.[277]

In the 1970s, bodybuilding had major publicity thanks to the appearance of Arnold Schwarzenegger, Franco Columbu, Lou Ferrigno, and others in the 1977 docudrama Pumping Iron. By this time, the IFBB dominated the competitive bodybuilding landscape and the Amateur Athletic Union (AAU) took a back seat. The National Physique Committee (NPC) was formed in 1981 by Jim Manion,[7] who had just stepped down as chairman of the AAU Physique Committee. The NPC has gone on to become the most successful bodybuilding organization in America and is the amateur division of the IFBB. The late 1980s and early 1990s saw the decline of AAU-sponsored bodybuilding contests. In 1999, the AAU voted to discontinue its bodybuilding events.
Prohormones are precursors to hormones and are most typically sold to bodybuilders as a precursor to the natural hormone testosterone. This conversion requires naturally occurring enzymes in the body. Side effects are not uncommon, as prohormones can also convert further into DHT and estrogen. To deal with this, many supplements also have aromatase inhibitors and DHT blockers such as chrysin and 4-androstene-3,6,17-trione. To date most prohormone products have not been thoroughly studied, and the health effects of prolonged use are unknown. Although initially available over the counter, their purchase was made illegal without a prescription in the US in 2004, and they hold similar status in many other countries. They remain legal, however, in the United Kingdom and the wider European Union. Their use is prohibited by most sporting bodies.
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.

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(9):1099-1104. View abstract.
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]
Glutamine and beta-alanine are amino acids and HMB, beta-hydroxy-beta-methyl butyrate, is a byproduct of leucine, another amino acid. Promoting individual amino acids, the building blocks of protein, to enhance performance in the strength sports has been a particular focus of supplement manufacturers over the years. To date, the evidence for any advantage has been mixed and mostly unimpressive.
"Start with two days for two to three weeks, then add a third day," says Davis*.*"Ideally, you should strength train three to five days per week, but work your way up—starting off at five days a week might shock your body." Here's a comprehensive three-day-per-week plan to get you started. Aim to complete 20-minute sessions, then gradually add on time in ten-minute increments until you're working for 45 to 60 minutes, suggests Davis.
How to do it: In general, your feet should be shoulder-width or slightly wider apart (if you’ve got a bigger frame go wider; if you’re smaller, go closer together), and your feet planted firmly on the floor, driving and emphasizing that heel drive. Stand tall. Depending on your preference or what’s available, hold a dumbbell in each hand (arms down at your sides); position yourself under a barbell with the bar against your traps for a back squat, and just over your chest for a front squat; hold a kettbell or dumbbell at your chest for goblet squats; wrap resistance bands under your feet and around your shoulders; or, use just your bodyweight to perform a basic squat.

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.
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]
A typical creatine supplementation protocol consists of a loading phase of 20 g CM/d or 0.3 g CM/kg/d split into 4 daily intakes of 5 g each, followed by a maintenance phase of 3-5 g CM/d or 0.03 g CM/kg/d for the duration of the supplementation period [5]. Other supplementation protocols are also used such as a daily single dose of around 3 – 6 g or between 0.03 to 0.1 g/kg/d [15,55] however this method takes longer (between 21 to 28 days) to produce ergogenic effects [5]. Sale et al [56] found that a moderate protocol consisting of 20 g CM taken in 1g doses (evenly ingested at 30-min intervals) for 5 days resulted in reduced urinary creatine and methylamine excretion, leading to an estimated increase in whole body retention of creatine (+13%) when compared with a typical loading supplementation protocol of 4 x 5 g/d during 5 days (evenly ingested at 3 hour intervals). This enhancement in creatine retention would lead to a significantly higher weight gain when people follow a moderate protocol ingestion of several doses of small amounts of CM evenly spread along the day.
Discomfort can arise from other factors. Individuals who perform large numbers of repetitions, sets, and exercises for each muscle group may experience a burning sensation in their muscles. These individuals may also experience a swelling sensation in their muscles from increased blood flow (the "pump"). True muscle fatigue is experienced as a marked and uncontrollable loss of strength in a muscle, arising from the nervous system (motor unit) rather than from the muscle fibers themselves. Extreme neural fatigue can be experienced as temporary muscle failure. Some weight training programs, such as Metabolic Resistance Training, actively seek temporary muscle failure; evidence to support this type of training is mixed at best.[24] Irrespective of their program, however, most athletes engaged in high-intensity weight training will experience muscle failure during their regimens.
Creatine may preserve dopamine synthesis in the striatum of mice (while protecting against dopaminergic depletion) when fed to mice at 2% of the diet for one week prior to MPTP toxicity[230]. This is possibly secondary to increasing tyrosine hydroxylase activity, the rate-limiting step of dopamine biosynthesis.[210][235] Two percent creatine was as protective as 0.005% rofecoxib (a COX2 inhibitor), but the two were additive in their protective effects (highly synergistic in regard to DOPAC by normalizing it, but not synergistic in preserving HVA).[230]
Weight trainers commonly spend 5 to 20 minutes warming up their muscles before starting a workout. It is common to stretch the entire body to increase overall flexibility; however, many people stretch just the area being worked that day. The main reason for warming up is injury prevention. Warming up increases blood flow and flexibility, which lessens the chance of a muscle pull or joint pain.

I can’t predict what sort of results you’ll see in that first year, but it can be pretty epic if you attack it right! Muscle growth might happen slower than you want, but I expect something different will happen along the way – you’ll fall in love with this idea of building STRENGTH! In fact, getting hooked on progress, and strength training is one of the best things you can do for yourself.
In young rats given creatine in the diet at 2% of the diet for eight weeks, supplementation appears to increase bone mineral density (BMD) in the lumbar spine with a nonsignificant trend to increase BMD in the femur.[426] Despite the trend, the femur appeared to be 12.3% more resistant to snapping from mechanical stress associated with increased thickness.[426] Menopausal rats (ovarectomized) experience similar benefits, as supplementation of creatine (300mg/kg) for eight weeks during ovarectomy is able to increase phosphorus content of the bone and other biomarkers of bone health, although bone stress resistance was not tested.[427]
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(9):1099-1104. View abstract.
You can't scroll through Instagram without clocking a mammoth cheat day feast, but are real-life bodybuilders consuming such a crazy amount of calories every couple of weeks? Not quite. When he’s dieting for a competition, Terry incorporates ‘re-feed days’ into his schedule. This means he eats the exact same food, but essentially doubles the portion sizes.
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