In standard dosages (5-10g creatine monohydrate) the bioavailability of creatine in humans is approximately 99%, although this value is subject to change with different conjugates (forms) of creatine and dosages. Coingestion of cyclocreatine (an analogue) can reduce uptake by about half and coincubation of taurine, choline, glycine, or beta-alanine had minimal attenuation of absorption, which is likely not practically relevant. The inhibition noted with cyclocreatine may be due to receptor saturation.
Tough workouts drive muscle growth, but they generally cause a lot of damage to your muscles to do so. This damage often results in soreness for several days, which can make it tough to get to the gym or sometimes even move. Many bodybuilding supplements contain ingredients that work to reduce the breakdown of muscle during workouts, making the recovery process easier on the body.
^ Southren AL, Gordon GG, Tochimoto S, Pinzon G, Lane DR, Stypulkowski W (May 1967). "Mean plasma concentration, metabolic clearance and basal plasma production rates of testosterone in normal young men and women using a constant infusion procedure: effect of time of day and plasma concentration on the metabolic clearance rate of testosterone". The Journal of Clinical Endocrinology and Metabolism. 27 (5): 686–94. doi:10.1210/jcem-27-5-686. PMID 6025472.
Most people require around 20 calories per pound (or 44 kcal / kg) of bodyweight to gain muscle mass. Using a 180-pound (82kg) male as an example, the required daily calorie intake is 3600 calories (20 kcal x 180 lb = 3600 kcal). When it comes to gaining weight, it is likely that you may put on a few pounds of fat along the way, but if you do find your body fat increasing, either increase the amount of aerobic exercise (moderate intensity) you are doing or slightly reduce the total number of calories you are consuming. Remember you can’t force feed muscle gain!
The concentration in healthy controls (57+/-8 years) without supplementation of creatine appears to be around 1.24+/-0.26µM per gram of hemoglobin and appears to decrease in concentration during the aging process of the erythrocyte. Otherwise healthy subjects who take a loading phase of creatine (5g four times daily for five days) can experience a 129.6% increase in erythrocytic creatine concentrations from an average value of 418µM (per liter) up to 961µM with a large range (increases in the range of 144.4-1004.8µM), and this effect appears to correlate somewhat with muscular creatine stores.
Cornelissen et al  analyzed the effects of 1 week loading protocol (3 X 5 g/d CM) followed by a 3 month maintenance period (5 g/d) on cardiac patients involved in an endurance and resistance training program. Although CM supplementation did not significantly enhance performance, markers of renal and liver function were within normal ranges indicating the safety of the applied creatine supplementation protocol.
Creatine ethyl ester is more a pronutrient for creatinine rather than creatine, and was originally created in an attempt to bypass the creatine transporter. It is currently being studied for its potential as a treatment for situations in which there is a lack of creatine transporters (alongside cyclocreatine as another possible example). Its efficacy may rely on intravenous administration, however.
An odd exercise that will integrate both sides of the back of your body in it’s natural “cross-pattern” activation. Basically, when one glute fires, the opposing low back muscle fires as well. This naturally happens when walking, running, or walking up stairs. It’s a great exercise for this muscle firing pattern and to get your glutes working hard. Plus, it looks cool.
Bodybuilding developed in the late 19th century, promoted in England by German Eugen Sandow, now considered as the "Father of Bodybuilding". He allowed audiences to enjoy viewing his physique in "muscle display performances". Although audiences were thrilled to see a well-developed physique, the men simply displayed their bodies as part of strength demonstrations or wrestling matches. Sandow had a stage show built around these displays through his manager, Florenz Ziegfeld. The Oscar-winning 1936 musical film The Great Ziegfeld depicts the beginning of modern bodybuilding, when Sandow began to display his body for carnivals.
So how does that play out in the real world? Well, if, for example, a woman adds 10 pounds of muscle and loses 10 pounds of fat, she’ll burn 40 extra calories per day. Forty calories a day isn’t nearly as significant as a dietary change could be, but for people who are looking to lose weight, it can still make a minor difference over the long term.
The last survivors of the pro-hormone supplements, which were removed from sale last January, estrogen-blocking supplements aren't pro-hormones but do inhibit the enzyme aromatase, which converts androgens into estrogens. In normal men that enzyme is ubiquitous, being present in such tissues as muscle, brain and skin. About 20 percent of the free testosterone circulating in the blood is converted into estrogen by way of aromatase.
Helping with running and other higher intensity activities that involve lift off — Some research has found that while the gluteus maximus supports lower levels of activity (like walking uphill or on an even surface) in certain ways, it’s strength is required much more for activities that require speed, such as jumping or running. In fact, some researchers believe that growth of the glutes in humans and other primates is tied to the evolution of running capabilities.
Replacement therapy may produce desired results, such as greater muscle mass and a stronger sex drive. However, the treatment does carry some side effects. Oily skin and fluid retention are common. The testicles may also shrink, and sperm production could decrease significantly. Some studies have found no greater risk of prostate cancer with testosterone replacement therapy, but it continues to be a topic of ongoing research.
Creatine is known to occur in highly concetrated levels in chicken photoreceptors, relative to other parts of the eye (10-15mM) alongside high levels of creatine kinase. The creatine transporter in human eyes also seems to be concentrated in the photoreceptors, which are known to be susceptible to hypoxic cellular death which, for humans, usually means retinal detachment.