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]

In the last week leading up to a contest, bodybuilders usually decrease their consumption of water, sodium, and carbohydrates, the former two to alter how water is retained by the body and the latter to reduce glycogen in the muscle. The day before the show, water is removed from the diet, and diuretics may be introduced, while carbohydrate loading is undertaken to increase the size of the muscles through replenishment of their glycogen. The goal is to maximize leanness and increase the visibility of veins, or "vascularity". The muscular definition and vascularity are further enhanced immediately before appearing on stage by darkening the skin through tanning products and applying oils to the skin to increase shine. Some competitors will eat sugar-rich foods to increase the visibility of their veins. A final step, called "pumping", consists in performing exercises with light weights or other kinds of low resistance (for instance two athletes can "pump" each other by holding a towel and pulling in turn), just before the contest, to fill the muscles with blood and further increase their size and density.
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].

Maughan RJ, King DS, Lea T. Dietary supplements. J Sports Sci. 2004 Jan;22(1):95-113.Kreider RB. Dietary supplements and the promotion of muscle growth with resistance exercise. Sports Med. 1999 Feb;27(2):97-110.Kerksick CM, Rasmussen CJ, Lancaster SL, et al. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. 2006 Aug;20(3):643-53.Update of Cochrane Database Syst Rev. 2001;(1):CD002946. Glucosamine therapy for treating osteoarthritis. Cochrane Database Syst Rev. 2005 Apr 18;(2):CD002946.AIS Sports Nutrition - AIS Sports Supplement Program 2007.
It’s true—your genes can play a role when it comes to building muscle. In general, there are two types of muscle fibers: Type I, which are slow twitch, and Type II, which are fast twitch. Depending on which you have more of, you may have an easier or harder time gaining muscle. “Fast twitch muscle fibers are two times as thick as slow twitch muscle fibers, lending to the overall thickness of the muscle without any activity,” explains Lovitt. “Those people with a genetic predisposition of a high percentage of these fibers can increase muscle size very easily while the people with a higher percentage of slow twitch muscle fibers have to work really hard to put on mass.” It’s the reason why a world-class sprinter genetically has more fast twitch muscle fibers than a world-class marathoner—it comes down to what we’re born with.
Miscellaneous: Sleep: (REM sleep) increases nocturnal testosterone levels.[146] Behavior: Dominance challenges can, in some cases, stimulate increased testosterone release in men.[147] Drugs: Natural or man-made antiandrogens including spearmint tea reduce testosterone levels.[148][149][150] Licorice can decrease the production of testosterone and this effect is greater in females.[151]

The amount of testosterone synthesized is regulated by the hypothalamic–pituitary–testicular axis (see figure to the right).[133] When testosterone levels are low, gonadotropin-releasing hormone (GnRH) is released by the hypothalamus, which in turn stimulates the pituitary gland to release FSH and LH. These latter two hormones stimulate the testis to synthesize testosterone. Finally, increasing levels of testosterone through a negative feedback loop act on the hypothalamus and pituitary to inhibit the release of GnRH and FSH/LH, respectively.
Multivitamin: A bodybuilder’s regime is strict and consuming the essential nutrients is an integral part of the process. The entire process can take a very nasty turn if one is not careful with the amount and type of food intake. The intake of multi vitamins can, therefore, have a good impact on a body builder. These multivitamins are used so that essential vitamins and minerals are supplied to the body, to promote good health and also allow a constant flow of energy.
Saw palmetto: Uses, dosage, and side effects Saw palmetto is an extract from the berries of a type of palm tree. The berries have traditionally been used to ease urinary and reproductive problems. The extract is now used in herbal remedies to stabilize testosterone. Learn about its use, its effectiveness, the science behind the claims, and any side effects. Read now
Need the motivation to push past your comfort zone and squeeze out one more push-up or bicep curl? Sure, it helps to remember that you’ll get stronger, rock more toned muscles and rev your metabolism, thanks to all that added muscle mass. But if that wasn’t enough, now comes news that all that pump-itude (yes, that’s an SNL reference) has psychological benefits, too.
AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS Find an Orthopaedist program on this website.
Testosterone is also important for maintaining bone strength and lean muscle mass in women, as well as contributing to overall well-being and energy levels. This hormone plays a key role in a woman’s sex drive and is responsible for enhancing sexual pleasure during intercourse. However, the levels of testosterone produced by females is still between ten and times less than the amount produced by men.

Polyethylene glycol is a non-toxic, water-soluble polymer that is capable of enhancing the absorption of creatine and various other substances [66]. Polyethylene glycol can be bound with CM to form polyethylene glycosylated creatine. One study [67] found that 5 g/d for 28 days of polyethylene glycosylated creatine was capable of increasing 1RM bench press in 22 untrained young men but not for lower body strength or muscular power. Body weight also did not significantly change in the creatine group which may be of particular interest to athletes in weight categories that require upper body strength. Herda et al [68] analyzed the effects of 5 g of CM and two smaller doses of polyethylene glycosylated creatine (containing 1.25 g and 2.5 g of creatine) administered over 30 days on muscular strength, endurance, and power output in fifty-eight healthy men. CM produced a significantly greater improvement in mean power and body weight meanwhile both CM and polyethylene glycosylated form showed a significantly (p < 0.05) greater improvement for strength when compared with control group. These strength increases were similar even though the dose of creatine in the polyethylene glycosylated creatine groups was up to 75% less than that of CM. These results seem to indicate that the addition of polyethylene glycol could increase the absorption efficiency of creatine but further research is needed before a definitive recommendation can be reached.
For many people, appearance is the top priority when it comes to their posterior. But yoga practitioners also know that the glute muscles can do so much more than look great in jeans: They’re the primary players in many of the movements that make it possible to do yoga. The gluteus maximus, medius, and minimus—along with many other smaller, supporting muscles—act as a base of support for the pelvis and hips. What’s more, these hard-working muscles stabilize your femur (thighbone) in your hip socket, rotate your femur internally and externally, and draw your leg back. And yes, all of these actions also help us stand and walk, and even support us when we sit.
There are several different available forms of creatine: creatine anhydrous which is creatine with the water molecule removed in order to increase the concentration of creatine to a greater amount than that found in CM. Creatine has been manufactured in salt form: creatine pyruvate, creatine citrate, creatine malate, creatine phosphate, magnesium creatine, creatine oroate, Kre Alkalyn (creatine with baking soda). Creatine can also be manufactured in an ester form. Creatine ethyl ester (hydrochloride) is an example of this, as is creatine gluconate which is creatine bound to glucose. Another form is creatine effervescent which is creatine citrate or CM with citric acid and bicarbonate. The citric acid and bicarbonate react to produce an effervescent effect. When mixed with water the creatine separates from its carrier leaving a neutrally charged creatine, allowing it to dissolve to a higher degree in water. Manufacturers claim that creatine effervescent has a longer and more stable life in solution. When di-creatine citrate effervescent was studied [59] for stability in solution it was found that the di-creatine citrate dissociates to citric acid and creatine in aqueous solutions which in turn forms CM and eventually crystallises out of the solution due to its low solubility. Some of the creatine may also convert to creatinine.
As scientific research progressed, it became apparent that the best types of protein came from milk and eggs. That led to the next great revolution in sports nutrition, namely the engineered food, pioneered by Scott Connelly, M.D., a critical care specialist from Northern California who teamed with a young entrepreneur named Bill Phillips from Golden, Colorado.
Great! Start with strength training 🙂 When you’re overweight, my guess is that you want to be preserving the muscle you have while losing the majority of your weight through fat. With strength training, your overall weight loss may seem slower, but you will lose inches faster. Strength training increases your metabolism; as long as you’re still eating in a deficit, you’ll lose weight.
The genealogy of lifting can be traced back to the beginning of recorded history[1] where humanity's fascination with physical abilities can be found among numerous ancient writings. In many prehistoric tribes, they would have a big rock they would try to lift, and the first one to lift it would inscribe their name into the stone. Such rocks have been found in Greek and Scottish castles.[2] Progressive resistance training dates back at least to Ancient Greece, when legend has it that wrestler Milo of Croton trained by carrying a newborn calf on his back every day until it was fully grown. Another Greek, the physician Galen, described strength training exercises using the halteres (an early form of dumbbell) in the 2nd century.
Ancient Greek sculptures also depict lifting feats. The weights were generally stones, but later gave way to dumbbells. The dumbbell was joined by the barbell in the later half of the 19th century. Early barbells had hollow globes that could be filled with sand or lead shot, but by the end of the century these were replaced by the plate-loading barbell commonly used today.[3]

show that total testosterone levels increase after exercising, especially after resistance training. Low testosterone levels can affect your sex drive and your mood. The good news is that exercise improves mood and stimulates brain chemicals to help you feel happier and more confident. Exercise also boosts energy and endurance, and helps you to sleep better. Fitness experts recommend 30 minutes of exercise every day.

If you have been diagnosed with a certain testosterone deficiency, ask your doctor and/or pharmacist to see if TestoFuel could be beneficial for you. Aside from balancing your testosterone, you may experience increased muscle strength while using this supplement during your intense exercise routine. Here are certain instances where TestoFuel could help correct your testosterone problems:
The important role of nutrition in building muscle and losing fat means bodybuilders may consume a wide variety of dietary supplements.[41] Various products are used in an attempt to augment muscle size, increase the rate of fat loss, improve joint health, increase natural testosterone production, enhance training performance and prevent potential nutrient deficiencies.
When lifting to complete fatigue, it takes an average of two to five minutes for your muscles to rest for the next set. When using lighter weight and more repetitions, it takes between 30 seconds and a minute for your muscles to rest. For beginners, working to fatigue isn't necessary, and starting out too strong can lead to too much post-exercise soreness.
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.
The chemical synthesis of testosterone from cholesterol was achieved in August that year by Butenandt and Hanisch.[188] Only a week later, the Ciba group in Zurich, Leopold Ruzicka (1887–1976) and A. Wettstein, published their synthesis of testosterone.[189] These independent partial syntheses of testosterone from a cholesterol base earned both Butenandt and Ruzicka the joint 1939 Nobel Prize in Chemistry.[187][190] Testosterone was identified as 17β-hydroxyandrost-4-en-3-one (C19H28O2), a solid polycyclic alcohol with a hydroxyl group at the 17th carbon atom. This also made it obvious that additional modifications on the synthesized testosterone could be made, i.e., esterification and alkylation.

The process of phagocytosis (a macrophage consuming a pathogen) in macrophages appears to be associated with an acute reduction in creatine phosphate stores (45%)[436] and an increase in creatine kinase activity,[290] although prolonged stimulation is met with an increase in creatine phosphate (20%).[290] The creatine kinase activity does not appear to be altered based on creatine availability,[290] but since ATP seems to be preserved in these instances,[436][290] the increase in phosphocreatine may be explained by an overall creatine pool paralleling that found in medium.[290]
You are encouraged to confirm information obtained from or through this website with other sources. Our content is not a substitute for qualified medical advice. The supplement summaries on this website may not include all the information pertinent to your use. Before starting a diet, taking new supplements, or beginning an exercise program, check with your doctor to clear any lifestyle changes. Only your doctor can determine what is right for you based on your medical history and prescriptions.
Escolar, D. M., Buyse, G., Henricson, E., Leshner, R., Florence, J., Mayhew, J., Tesi-Rocha, C., Gorni, K., Pasquali, L., Patel, K. M., McCarter, R., Huang, J., Mayhew, T., Bertorini, T., Carlo, J., Connolly, A. M., Clemens, P. R., Goemans, N., Iannaccone, S. T., Igarashi, M., Nevo, Y., Pestronk, A., Subramony, S. H., Vedanarayanan, V. V., and Wessel, H. CINRG randomized controlled trial of creatine and glutamine in Duchenne muscular dystrophy. Ann Neurol 2005;58(1):151-155. View abstract.
The G-med and G-min perform similar functions, depending on the position of the knee and hip joints. With the knee extended, they abduct the thigh (out to the side away from the opposite leg). When running, they stabilize the leg during the single-support phase. With the hips flexed, they internally rotate the thigh. With the hips extended, they externally rotate the thigh.
There are many potential reasons, but I am going to keep it simple and give you just two. The first and most common reason people suffer from underactive glutes or “glute amnesia” is due to lifestyle. Even when people train hard every day, if they spend the majority of the remainder of the day sitting down, then they are simply not using their glutes. And remember the old saying - if you don’t use it, you lose it. Unfortunately, this is just what happens with your glutes.
A study using creatine at 0.02% of a face cream (confounded with 8% glycerol and 0.4% Guarana) was able to exert a skin-tightening effect over 6 weeks, reducing wrinkles and jowl volume.[541] Combination therapy has also been used with creatine and folic acid (both in vitro[543] and in vivo), resulting in increased skin firmness and reduced coarse and fine wrinkles.[544]
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.

Elsewhere, it has been noted that in chronic progressive external ophthalmoplegia (CPEO, a progressive weakening of the muscles around the eye and a mitochondrial disorder), there was a failure of creatine supplementation to benefit symptoms when subjects were provided 20g daily for four weeks.[483] Creatine supplementation failed again at 150mg/kg for six weeks in people with either CPEO or another disorder associated with single gene deletions affecting the eyes (Kearns–Sayre syndrome, KSS) in improving muscular function.[484]

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. 
Creatine has been shown to influence androgen levels. Three weeks of creatine supplementation has been shown to increase dihydrotestosterone (DHT) levels, as well as the DHT:testosterone ratio with no effects on testosterone levels.[430] In contrast, creatine supplementation has been shown to increase testosterone levels when taken alongside a 10-week resistance training program.[431] A study in male amateur swimmers also noted that a creatine loading phase (20g daily for six days) was able to increase testosterone levels by around 15% relative to baseline.[397] 
It arises from the posterior gluteal line of the inner upper ilium, a pelvic bone, and roughly the portion of the bone including the crest of the ilium (the hip bone), immediately above and behind it; and from the posterior surface of the lower part of the sacrum, the base of the spine, and the side of the coccyx, the tailbone; from the aponeurosis of the erector spinae (lumbodorsal fascia), the sacrotuberous ligament, and the fascia covering the gluteus medius (gluteal aponeurosis). The fibers are directed obliquely downward and lateralward; The gluteus maximus has two insertions:
It was traditionally thought that total brain blood flow was not changed during physical activity. Research in the last 10 years, however, changed this perspective. We now understand that the increased neuronal and metabolic activity of the brain during exercise drive increases in blood flow to it. We have also learned that exercise that is too intense will reduce blood flow and oxygen delivery causing fatigue. So, what is the ideal intensity to stimulate blood flow to the brain, and perhaps, augment your mental abilities in the moment?

Entry into neural tissues in general is mediated by the secondary creatine transporter (CrT-2) known as SLC6A10,[186] which is the same transporter that is active in a male’s testicles.[145] CrT-2 belongs to the family of SLC6 transporters that act to move solutes across the membrane by coupling transport with sodium and chloride.[187][188] Genetic deletions in the 16p11.2 region, which encodes both SLC6A8[189] and SLC6A10[186] can result in severe mental retardation in humans and is one of the causes of “Creatine Deficiency Syndrome.” Creatine Deficiency Syndrome is not only caused by lack creatine transporter expression, however, as creatine synthesis is also critical for neural function.[190].[189] Retardation caused by defective creatine synthesis[31] can be reversed with creatine supplementation and dietary changes.[191]
Take time to rest. To give your muscles time to recover, rest one full day between exercising each specific muscle group. You might choose to work the major muscle groups at a single session two or three times a week, or plan daily sessions for specific muscle groups. For example, on Monday work your arms and shoulders, on Tuesday work your legs, and so on.
Bodybuilders have THE BEST mind to muscle connection of any resistance-training athletes. Ask a seasoned bodybuilder to flex their lats or their rhomboids or their hamstrings and they will do it with ease. Ask other strength athletes and you will see them struggle and although they may tense up the target muscle they will also tense up about 15 other surrounding muscles. This is because strength athletes train MOVEMENTS. They don’t care about targeting their lats. They just want to do the most pull ups. They don’t worry about feeling their quads. They just want to squat maximum weight. Although this is an expected and positive thing for the most part, there are real benefits to being able to isolate and target muscles.
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.
"A lot of the symptoms are mirrored by other medical problems," Hedges says. "And for a long time, we were not attributing them to low testosterone, but to diabetes, depression, high blood pressure, and coronary artery disease. But awareness and appreciation of low testosterone has risen. We recognize now that low testosterone may be at the root of problems."

In particular situations, a coach may advise performing the valsalva maneuver during exercises which place a load on the spine. The vasalva maneuver consists of closing the windpipe and clenching the abdominal muscles as if exhaling, and is performed naturally and unconsciously by most people when applying great force. It serves to stiffen the abdomen and torso and assist the back muscles and spine in supporting the heavy weight. Although it briefly increases blood pressure, its is still recommended by weightlifting experts such as Rippetoe since the risk of a stroke by aneurysm is far lower than the risk of an orthopedic injury caused by inadequate rigidity of the torso.[10] Some medical experts warn that the mechanism of building "high levels of intra-abdominal pressure (IAP)...produced by breath holding using the Valsava maneuver", to "ensure spine stiffness and stability during these extraordinary demands", "should be considered only for extreme weight-lifting challenges — not for rehabilitation exercise".[11]
Duchenne’s Muscular Dystrophy (DMD) is associated with a reduction in intracellular creatine stores[554] known to only affects males. It is an X-linked progressive myopathy associated with abnormalities in the dystrophin gene.[555] The standard therapy at this moment involves corticosteroids such as prednisone.[556][557] Creatine is thought to be therapeutic since the known targetable abnormalities in DMD (impairment in protein synthesis associated with oxidative stress and increased protein breakdown) is a property of creatine and supplementation showed promise in the first case study[558] and benefit in a group of mixed dystrophinopathies.[559]
Creatine monohydrate is regarded as a necessity by most bodybuilders. Creatine monohydrate is the most cost-effective dietary supplement in terms of muscle size and strength gains. … There is no preferred creatine supplement, but it is believed that creatine works best when it is consumed with simple carbohydrates. This can be accomplished by mixing powdered creatine with grape juice, lemonade, or many high glycemic index drinks.[36]

Unlike women, who experience a rapid drop in hormone levels at menopause, men experience a more gradual decrease of testosterone levels over time. The older the man, the more likely he is to experience below-normal testosterone levels. Men with testosterone levels below 300 ng/dL may experience some degree of low T symptoms. Your doctor can conduct a blood test and recommend treatment if needed. They can discuss the potential benefits and risks of testosterone medication, as well.


Perform bent over rows to work your back. Stand with your feet shoulder-width apart, about 6 to 10 inches (15–25 cm) behind the barbell or two dumbbells. Bend slightly at the knees but keep your shins vertical. Bend forward at the waist with your spine and head straight. Lift the weight with an overhand grip up to your lower chest or upper abdomen. Lower slowly until your arms are nearly extended, without touching the ground. 3 x 8.[5]
The important role of nutrition in building muscle and losing fat means bodybuilders may consume a wide variety of dietary supplements.[41] Various products are used in an attempt to augment muscle size, increase the rate of fat loss, improve joint health, increase natural testosterone production, enhance training performance and prevent potential nutrient deficiencies.
Men who watch a sexually explicit movie have an average increase of 35% in testosterone, peaking at 60–90 minutes after the end of the film, but no increase is seen in men who watch sexually neutral films.[43] Men who watch sexually explicit films also report increased motivation, competitiveness, and decreased exhaustion.[44] A link has also been found between relaxation following sexual arousal and testosterone levels.[45]
The chemical synthesis of testosterone from cholesterol was achieved in August that year by Butenandt and Hanisch.[188] Only a week later, the Ciba group in Zurich, Leopold Ruzicka (1887–1976) and A. Wettstein, published their synthesis of testosterone.[189] These independent partial syntheses of testosterone from a cholesterol base earned both Butenandt and Ruzicka the joint 1939 Nobel Prize in Chemistry.[187][190] Testosterone was identified as 17β-hydroxyandrost-4-en-3-one (C19H28O2), a solid polycyclic alcohol with a hydroxyl group at the 17th carbon atom. This also made it obvious that additional modifications on the synthesized testosterone could be made, i.e., esterification and alkylation.
The chemical synthesis of testosterone from cholesterol was achieved in August that year by Butenandt and Hanisch.[188] Only a week later, the Ciba group in Zurich, Leopold Ruzicka (1887–1976) and A. Wettstein, published their synthesis of testosterone.[189] These independent partial syntheses of testosterone from a cholesterol base earned both Butenandt and Ruzicka the joint 1939 Nobel Prize in Chemistry.[187][190] Testosterone was identified as 17β-hydroxyandrost-4-en-3-one (C19H28O2), a solid polycyclic alcohol with a hydroxyl group at the 17th carbon atom. This also made it obvious that additional modifications on the synthesized testosterone could be made, i.e., esterification and alkylation.

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]

The chemical synthesis of testosterone from cholesterol was achieved in August that year by Butenandt and Hanisch.[188] Only a week later, the Ciba group in Zurich, Leopold Ruzicka (1887–1976) and A. Wettstein, published their synthesis of testosterone.[189] These independent partial syntheses of testosterone from a cholesterol base earned both Butenandt and Ruzicka the joint 1939 Nobel Prize in Chemistry.[187][190] Testosterone was identified as 17β-hydroxyandrost-4-en-3-one (C19H28O2), a solid polycyclic alcohol with a hydroxyl group at the 17th carbon atom. This also made it obvious that additional modifications on the synthesized testosterone could be made, i.e., esterification and alkylation.
In summary, creatine salts have been show to be less stable than CM. However the addition of carbohydrates could increase their stability [62]. The potential advantages of creatine salts over CM include enhanced aqueous solubility and bioavailability which would reduce their possible gastrointestinal adverse effects [63]. The possibility for new additional formulation such as tablets or capsules is interesting for its therapeutic application due to its attributed better dissolution kinetics and oral absorption compared to CM [63]. However more complete in vivo pharmaceutical analysis of creatine salts are required to fully elucidate their potential advantages/disadvantages over the currently available supplement formulations.
The structure of cyclocreatine is fairly flat (planar), which aids in passive diffusion across membranes. It has been used with success in an animal study, where mice suffered from a SLC6A8 (creatine transporter at the blood brain barrier) deficiency, which is not responsive to standard creatine supplementation.[97] This study failed to report increases in creatine stores in the brain, but noted a reduction of mental retardation associated with increased cyclocreatine and phosphorylated cyclocreatine storages.[97] As demonstrated by this animal study and previous ones, cyclocreatine is bioactive after oral ingestion[97][98] and may merely be a creatine mimetic, able to phosphorylate ADP via the creatine kinase system.[97]
×