Negative regulators of the creatine transporter (CrT) are those that, when activated, reduce the activity of the CrT and overall creatine uptake into cells. As noted above, CrT activity is positively regulated by mTOR. Consistent with the well-known role of AMPK as a suppressor mTOR signaling, CrT activity has also been shown to be inhibited in response to AMPK activation in kidney epithelial cells. Since AMPK suppresses mTOR via upstream TSC2 activation, the negative regulation of AMPK on CrT activity in these cells appears to occur through an indirect mechanism. Although indirect, activation of AMPK has been noted to reduce the Vmax of the CrT without altering creatine binding, and is involved in internalizing the receptors. This pathway seems to max out at around 30% suppression, with no combination of mTOR antagonists and AMPK inducers further suppressing creatine uptake.
Finally, starvation (nutrient deprivation for four days) appears to increase activity of the creatine transporter secondary to decreasing serine phosphorylation (SGK target) with no influence on tyrosine phosphorylation (c-Src target). Starvation-induced increases in creatine influx do not necessarily mean more phosphocreatine, however, due to a depleted cellular energy state.
Increasing creatine levels in skeletal muscle to 687% of baseline (0.5mM creatine, thought to be equivalent to 5g creatine) doesn’t seem to per se increase glucose uptake, but increases glucose oxidation (140% of baseline) which is due to a two-fold increase in the activity of α1 and α2 subunits of AMPK, a potency comparable to 1mM of the reference drug AICAR. Glucose uptake associated with AMPK has indeed been noted in diabetic people who are undergoing physical exercise and in contracting skeletal muscle cells, but according to rat and in vitro studies of cells not being contracted, this is not a per se effect of non-exercising tissue but an augmentation of exercise-induced glucose uptake.
Take your vitamins. In addition to a well-balanced diet, include a multivitamin supplement to your dietary regimen. It will ensure that your body is getting the full amount of vitamins and minerals it needs to stay healthy. There are many options, depending on your age, your sex, and your particular health and diet needs. Find the one that's right for you, and make it part of your daily routine.
I HATE that the resistance training community can be so tribal. I have been preaching to bodybuilders for years about the benefits of powerlifting, or Olympic lifting or kettlebells or even Crossfit style conditioning and many have been receptive. Learn from each other and achieve levels of fitness you simply could not have otherwise. Don’t brush off bodybuilding wisdom…it could be the missing factor in your program.
In addition to conjugation and the 17-ketosteroid pathway, testosterone can also be hydroxylated and oxidized in the liver by cytochrome P450 enzymes, including CYP3A4, CYP3A5, CYP2C9, CYP2C19, and CYP2D6. 6β-Hydroxylation and to a lesser extent 16β-hydroxylation are the major transformations. The 6β-hydroxylation of testosterone is catalyzed mainly by CYP3A4 and to a lesser extent CYP3A5 and is responsible for 75 to 80% of cytochrome P450-mediated testosterone metabolism. In addition to 6β- and 16β-hydroxytestosterone, 1β-, 2α/β-, 11β-, and 15β-hydroxytestosterone are also formed as minor metabolites. Certain cytochrome P450 enzymes such as CYP2C9 and CYP2C19 can also oxidize testosterone at the C17 position to form androstenedione.
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.
You've figured out the exercises you should be doing, but what about the number of sets and repetitions? Your decision should be based on your goals. The American College of Sports Medicine recommends 8-12 reps for muscular strength and 10-15 reps for muscular endurance. They also recommend at least 1 set of each exercise to fatigue although you'll find that most people perform about 2-3 sets of each exercise. In general:
If you are underweight or have a naturally scrawny build, you may struggle to gain weight, let alone muscle mass, no matter what you do. Eating at all hours of the day and night can be exhausting and require frequent trips to the grocery store. Unless you are overweight, you likely need to create a caloric surplus in order to gain muscle. With a weight gainer powder, you can supplement a healthy diet with the additional calories you need to gain weight in muscle.
At the time, low-potency creatine supplements were available in Britain, but creatine supplements designed for strength enhancement were not commercially available until 1993 when a company called Experimental and Applied Sciences (EAS) introduced the compound to the sports nutrition market under the name Phosphagen. Research performed thereafter demonstrated that the consumption of high glycemic carbohydrates in conjunction with creatine increases creatine muscle stores.
Studies conducted in rats have indicated that their degree of sexual arousal is sensitive to reductions in testosterone. When testosterone-deprived rats were given medium levels of testosterone, their sexual behaviors (copulation, partner preference, etc.) resumed, but not when given low amounts of the same hormone. Therefore, these mammals may provide a model for studying clinical populations among humans suffering from sexual arousal deficits such as hypoactive sexual desire disorder.
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.
There’s no need to go overboard on creatine intake, though, in search of crazy muscle growth: “The maximum amount of creatine that you can hold depends on the amount of muscle mass you have,” explains Bates. “So if you have more muscle, then your body can store more creatine. In general, the muscle can hold about 2 to 3 g of creatine per kilogram of muscle mass. So the amount of creatine you use will depend on the amount of muscle mass you have.” (7)
Rest and recovery is just as important as exercise, if not more so. Every time you do an intense workout, give yourself a minimum of 2 days to recuperate afterward, if not more. And don’t mix exercise with sleep hacking. If you’re exercising, get at least 8 hours of sleep every night. Your body uses it to rebuild, and you can throw your hormones out of whack if you don’t rest up properly. Here’s a more in-depth guide to Bulletproof weight training, complete with sample workouts.
^ Butenandt A, Hanisch G (1935). "Umwandlung des Dehydroandrosterons in Androstendiol und Testosterone; ein Weg zur Darstellung des Testosterons aus Cholestrin" [About Testosterone. Conversion of Dehydro-androsterons into androstendiol and testosterone; a way for the structure assignment of testosterone from cholesterol]. Hoppe-Seyler's Z Physiol Chem (in German). 237 (2): 89–97. doi:10.1515/bchm2.1935.237.1-3.89.
This period also saw the rise of anabolic steroids in bodybuilding and many other sports. In bodybuilding lore, this is partly attributed to the rise of "mass monsters", beginning with Arnold Schwarzenegger, Sergio Oliva, and Lou Ferrigno in the late 1960s and early 1970s, and continuing through the 1980s with Lee Haney, the 1990s with Dorian Yates, Ronnie Coleman, and Markus Rühl, and up to the present day. Bodybuilders such as Greg Kovacs attained mass and size never seen previously but were not successful at the pro level. Others were renowned for their spectacular development of a particular body part, like Tom Platz or Paul Demayo for the leg muscles. At the time of shooting Pumping Iron, Schwarzenegger (while never admitting to steroid use until long after his retirement) said that "you have to do anything you can to get the advantage in competition". He would later say that he does not regret using anything.
Creatine is stored in the body in the form of creatine and as creatine phosphate, otherwise known as phosphocreatine, which is the creatine molecule bound to a phosphate group. Creatine phosphate is thought to maintain the ATP/ADP ratio by acting as a high-energy phosphate reservoir. The more ATP a muscle has relative to ADP, the higher its contractility is, and thus its potential strength output in vivo. This pro-energetic mechanism also affects nearly all body systems, not just skeletal muscle.  During periods of rest and anabolism, creatine can gain a phosphate group through the creatine-kinase enzyme pathway, up to a cellular concentration of 30uM to be later used for quick ATP resupply, when needed.
First off, every single resistance-training athlete in the world should be very thankful for bodybuilding training. It was bodybuilding that brought weight training to the mainstream. The bottom line is that the average gym goer is MORE interested in how they look vs. how they perform. 99% of every client I ever trained had an aesthetic goal as their primary goal. In my 20 plus years as a trainer I can count maybe 10 clients who said, “My goal is to be able to bench press or squat or lift more weight.” It was the aesthetic focus of bodybuilding that opened the doors for all other resistance training pursuits to enter into the mainstream.
Firstly, let’s establish where your glutes are and what they actually refer to! Your ‘glutes’ — or your gluteal muscles, as they are more formally known — refer to the muscles in your butt. Specifically, there are three major muscles in this area: your gluteus maximus (the main, large muscle that shapes your backside), your gluteus medius and your gluteus minimus (two smaller muscles that assist the gluteus maximus in moving your body).
The first thing you need is a weight training program that signals the muscle building process to begin. Research has shown that a well designed program will generate this “signal” via a combination of progressive tension overload (as in, getting stronger over time), metabolic stress (as in, fatiguing the muscle and getting “the pump”), and muscular damage (as in, actual damage to the muscle tissue itself).
Do you know what happens when a person attempts to build muscle faster than they legitimately can? They fail, and then they wonder why it’s not working as quickly as they thought it would. From there, they’ll jump from workout to workout, diet to diet and useless supplement to useless supplement in the hopes of finally finding the missing link that will make it happen. But they’re never going to find it. They’ll just keep wasting their time, effort and money searching for something that doesn’t exist.