Our Keep-It™ guarantee is valid for the first-time purchase of a formula, and redeemable up to three months (90 days) after the purchase date. Multiple bottles, foods, apparel and gear do not fall under this guarantee, however, they may be applicable for return. Fitness equipment, personal care products, knowledge purchases, and DVDs are not eligible for return or refund. For more information and a full list of products that qualify, visit our Keep-It™ page. Further details can be found on our Refund Policy support page.
Testosterone is observed in most vertebrates. Testosterone and the classical nuclear androgen receptor first appeared in gnathostomes (jawed vertebrates).[194] Agnathans (jawless vertebrates) such as lampreys do not produce testosterone but instead use androstenedione as a male sex hormone.[195] Fish make a slightly different form called 11-ketotestosterone.[196] Its counterpart in insects is ecdysone.[197] The presence of these ubiquitous steroids in a wide range of animals suggest that sex hormones have an ancient evolutionary history.[198]
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 4 to 6 reps for strength and hypertrophy, 8 to 12 reps for muscular strength and 10 to 15 reps for muscular endurance. They also recommend at least one set of each exercise to fatigue although you'll find that most people perform about 2 to 3 sets of each exercise. In general:

Creatine supplementation (11.4g) with glycerol (1g/kg; per se effective[394][395]) and glucose (75g) in endurance runners in the heat appears to attenuate the increase in internal temperature associated with an increase in total body water of 0.71+/-0.42L, while performance (VO2 max and running economy) were unaffected over 30 minutes.[3] Creatine is effective without glycerol (20g daily with 140g of glucose polymer over a week),[346] again without an improvement in physical performance.

It is possible that females could benefit more than males due to a combined lower creatine kinase activity as well as having altered purine metabolism during depression,[257] but no human comparative studies have been conducted yet. One rat study noted that creatine monohydrate at 2-4% of feed had 4% creatine able to exert anti-depressive and anxiolytic effects in female rats only.[228]
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.
The gluteus medius muscle originates on the outer surface of the ilium between the iliac crest and the posterior gluteal line above, and the anterior gluteal line below; the gluteus medius also originates from the gluteal aponeurosis that covers its outer surface. The fibers of the muscle converge into a strong flattened tendon that inserts on the lateral surface of the greater trochanter. More specifically, the muscle's tendon inserts into an oblique ridge that runs downward and forward on the lateral surface of the greater trochanter.
Research shows little evidence of abnormal or unhealthy psychological changes in men receiving supervised testosterone therapy to treat their low T, according to a study in the journal Therapeutics and Clinical Risk Management.However, mental and physical risks are involved in self-administration of artificial testosterone. Anyone abusing synthetic testosterone, also known as anabolic steroids, may experience episodes of aggressive or violent behavior, along with physical side effects. Bodybuilders, athletes, or anyone who seeks to build muscle mass or achieve other benefits from artificial testosterone should be aware of these risks.
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. 
Extracellular creatine (creatine outside of a cell) appears to influence creatine uptake into a cell. It seems that prolonged and excessive levels of creatine actually suppress uptake (a form of negative regulation to prevent excessive influx).[180] In vitro studies in rat muscle cells have shown that including 1mM creatine into cell culture medium substantially reduces creatine uptake into cells. The inhibitory effect was partially negated by protein synthesis inhibitors, suggesting that high levels of creatine induce the expression of a protein that suppresses creatine transporter activity.[180] Similar findings were reported in a later study in cultured mouse myoblasts, which noted a 2.4-fold increase in intracellular creatine levels in the presence of the protein synthesis inhibitor cyclohexamide.[174]
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]
The incidence of liver damage from herbal and dietary supplements is about 16–20% of all supplement products causing injury, with the occurrence growing globally over the early 21st century.[2] The most common liver injuries from weight loss and bodybuilding supplements involve hepatocellular damage with resulting jaundice, and the most common supplement ingredients attributed to these injuries are catechins from green tea, anabolic steroids, and the herbal extract, aegeline.[2]
Jason Ferruggia is a highly sought after, world renowned strength & conditioning specialist and muscle building expert. Over the last 17 years he has personally trained more than 700 athletes from over 90 different NCAA, NFL, NHL and MLB organizations. He has also worked extensively with firefighters, police officers, military personnel, Hollywood stars and entertainers. Most importantly, Jason has helped over 53,000 skinny guys and hard gainers in 126 different countries build muscle and gain weight faster than they every thought possible.
In males, the testosterone test can help find the reason for sexual problems, like reduced sex drive or erectile dysfunction. If you’re having a hard time getting your partner pregnant, the test can tell if your blood testosterone level is low. It can also screen for problems with the hypothalamus or pituitary gland. This controls how much testosterone your body makes.

Due to a combination of its neuroprotective effects and dopaminergic modulatory effects, creatine has been hypothesized in at least one review article to be of benefit to drug rehabilitation.[266] This study used parallels between drug abuse (usually methamphetamines) and traumatic brain injury[267][268] and made note of creatine being able to reduce symptoms of brain trauma, such as headaches, fatigue, and dizziness in clinical settings in two pilot studies.[269][270] No studies currently exist that examine creatine supplementation and drug rehabilitation.

Mercimek-Mahmutoglu, S., Stoeckler-Ipsiroglu, S., Adami, A., Appleton, R., Araujo, H. C., Duran, M., Ensenauer, R., Fernandez-Alvarez, E., Garcia, P., Grolik, C., Item, C. B., Leuzzi, V., Marquardt, I., Muhl, A., Saelke-Kellermann, R. A., Salomons, G. S., Schulze, A., Surtees, R., van der Knaap, M. S., Vasconcelos, R., Verhoeven, N. M., Vilarinho, L., Wilichowski, E., and Jakobs, C. GAMT deficiency: features, treatment, and outcome in an inborn error of creatine synthesis. Neurology 8-8-2006;67:480-484. View abstract.
2. What's your training like? Are you crushing 25 sets for chest like the average juiced out bodybuilder? If so, there's a pretty good chance you might be working above your MRV (maximal recoverable volume) and as such any physiological adaptation which could have taken place is going to be minimal given the cellular environment which occurs in a state of functional overreaching.
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.
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.
Remember that each person is unique, and each body responds differently to treatment. TT may help erectile function, low sex drive, bone marrow density, anemia, lean body mass, and/or symptoms of depression. However, there is no strong evidence that TT will help memory recall, measures of diabetes, energy, tiredness, lipid profiles, or quality of life.
The bulk of the gluteal muscle mass contributes only partially to shape of the buttocks. The other major contributing factor is that of the panniculus adiposus of the buttocks, which is very well developed in this area, and gives the buttock its characteristic rounded shape. The gluteal muscle bulk and tone can be improved with exercise. However, it is predominantly the disposition of the overlying panniculus adiposus which may cause sagging in this region of the body. Exercise in general (not only of the gluteal muscles but of the body in general) which can contribute to fat loss can lead to reduction of mass in subcutaneal fat storage locations on the body which includes the panniculus, so for leaner and more active individuals, the glutes will more predominantly contribute to the shape than someone less active with a fattier composition.[citation needed] The degree of body fat stored in various locations such as the panniculus is dictated by genetic and hormonal profiles.[citation needed]
Homocyteine (normal serum range of 5-14µM) is known to adversely affect motor control in genetically susceptible people when their levels exceed 500µM, which is usually associated with genetically induced deficiencies of B12.[360][361] In these particular instances (assessed by rats fed homocysteine to increase serum levels to such a high level[362][363]) it appears that administration of 50mg/kg creatine (injections) to these rats can protect dysfunction in muscle metabolism (pyruvate kinase activity, Krebs cycle intermediates, and muscle cell viability) induced by homocysteine.[363]
After the ingestion of 5g creatine in otherwise healthy humans, serum levels of creatine were elevated from fasting levels (50-100µM) to 600-800µM within one hour after consumption.[135] The receptor follows Michaelis-Menten kinetics with a Vmax obtained at concentrations higher than 0.3-0.4mmol/L,[136] with prolonged serum concentrations above this amount exerting most of its saturation within two days.[137]

As the name implies, the muscle power objective can be pursued if you want to achieve maximum size in your muscles or if you want them to be explosively strong (i.e. very powerful for short bursts at a time). In order to develop muscles this way you'll want to use no more than 3 sets in which no more than 8 reps are used. Muscle size and power is often used for muscles that are prominently displayed on the human figure, such as the pectorals, or the biceps and triceps.
After all, you’ve probably seen the countless workouts, diets, supplements, programs, products and people claiming that super fast muscle growth is possible. You’ve probably also seen the click-bait headlines (“How To Build 20lbs Of Muscle In Just 6 Weeks!”) and the unbelievable transformations of supposedly “natural” people (bodybuilders, celebrities, athletes, fitness gurus on social media, etc.) that clearly prove it can happen faster than this.
The Branched-Chain Amino Acids, BCAAs for short, are leucine, valine and isoleucine.  Essentially, its a form of protein powder for muscle gain or other uses. These essential amino acids are not made by the body but are found in foods such as meats, dairy products and legumes. In medicine, BCAAs are used for a number of conditions, however, for many uses, further research is necessary to determine whether or not treatment is effective.
The reasons for differences in the effect of creatine on testosterone vs. DHT across studies are not clear, but also not mutually exclusive. A measured increase in DHT could indicate that testosterone levels were increased by creatine, but rapidly converted to DHT through a homeostatic mechanism. Differences in study subject populations, methodology, or the presence and type of concurrent exercise could also be contributing factors. At any rate, the literature collectively suggests that creatine has the general ability to cause a modest increase in androgen levels in men.
Injections of creatine are known to be neuroprotective against low oxygen levels (hypoxia) even to neonatal rats.[532] This is thought to be associated with the increased collective pool of phosphocreatine and creatine.[236] Since oral ingestion of creatine by the mother increases brain concentrations of creatine by 3.6% in the fetus prior to birth,[531] it is thought to be protective in the fetuses subject to hypoxic (low oxygen) stressors, such as a caesarean section.
This cellular influx may also decrease protein oxidation rates, which leads to increases in nitrogen balance and indirectly increases muscle mass.[379] This lowering of protein oxidation is from signaling changes caused vicariously through cell swelling[380][381] and appears to upregulate 216 genes[378] in a range of 1.3 to 5-fold increases, with the largest increase seen in the protein involved in satellite cell recruitment, sphingosine kinase-1. Most importantly for muscle hypertrophy, the protein content of PKBa/Akt1, p38 MAPK, and ERK6 increased 2.8+/-1.2 fold.[378] Sixty-nine genes are also downregulated after creatine supplementation, to less notable degrees.
Keep in mind that while creatine boosts your performance in the gym, helping you achieve better muscle building results, it is also associated with some side effects. One of the main concerns is that creatine may worsen or cause kidney problems. Creatine shouldn’t be taken in combination with diabetes medications, acetaminophen, diuretics or caffeine. As always, speak with your doctor before taking supplements to make sure that the product is safe for you (6). Generally, for most people, the supplement is considered to be among the safer weight lifting supplements.

And not to drop a truth bomb but, most of us need to be doing glute exercises — and aren’t. “Lack of use is the biggest reason so many people tend to have weak glutes,” says Cassandra York, PhD, MS, RD, CSCS, best-selling fitness author and a professor at Central Connecticut State University. “We don’t walk as much as we used to. We don’t take the stairs. And when we do move, we tend to be quad dominant,” says York.


Why it works: The RDL, as it's known, is primarily a hamstrings move, but it’s also effective in building strength in your glutes, lower back, and upper back. Be sure to feel the "squeeze" in your hamstrings and glutes as you raise and lower the bar. For an even tougher variation that'll also increase your grip strength, try doing tempo RDLs—count a few seconds on your way up, and on your way down.
One rat study that compared male and female rats and used a forced swim test (as a measure of serotonergic activity of anti-depressants[227]) found that a sexual dimorphism existed, and females exerted a serotonin-mediated anti-depressant response while male rats did not.[228] It appears that these anti-depressive effects are mediated via the 5-HT1A subset of serotonin receptors, as the antidepressant effects can be abolished by 5-HT1A inhibitors.[229]
Creatine is a hydrophilic polar molecule that consists of a negatively charged carboxyl group and a positively charged functional group [64]. The hydrophilic nature of creatine limits its bioavailability [65]. In an attempt to increase creatines bioavailability creatine has been esterified to reduce the hydrophilicity; this product is known as creatine ethyl ester. Manufacturers of creatine ethyl ester promote their product as being able to by-pass the creatine transporter due to improved sarcolemmal permeability toward creatine [65]. Spillane et al [65] analyzed the effects of a 5 days loading protocol (0.30 g/kg lean mass) followed by a 42 days maintenance phase (0.075 g/kg lean mass) of CM or ethyl ester both combined with a resistance training program in 30 novice males with no previous resistance training experience. The results of this study [65] showed that ethyl ester was not as effective as CM to enhance serum and muscle creatine stores. Furthermore creatine ethyl ester offered no additional benefit for improving body composition, muscle mass, strength, and power. This research did not support the claims of the creatine ethyl ester manufacturers.
Attention, memory, and spatial ability are key cognitive functions affected by testosterone in humans. Preliminary evidence suggests that low testosterone levels may be a risk factor for cognitive decline and possibly for dementia of the Alzheimer's type,[104][105][106][107] a key argument in life extension medicine for the use of testosterone in anti-aging therapies. Much of the literature, however, suggests a curvilinear or even quadratic relationship between spatial performance and circulating testosterone,[108] where both hypo- and hypersecretion (deficient- and excessive-secretion) of circulating androgens have negative effects on cognition.
A good way to determine how much fat in grams you should be taking in is to multiply your calorie intake by 0.001 for maximum trans-fats; by 0.008 for maximum saturated fats; and by 0.03 for the "good fats". For example, for a 2,500-calorie diet, you would limit trans-fats to 3g or less, saturated fats to 20g or less, and up to 75g of mono- and polyunsaturated fats.

Creatine helps create essential adenosine triphosphate (ATP). This is the energy source of muscle contractions. By upping your levels, you can increase the amount of energy available to your muscles, boosting your performance. Because your muscle strength and size increases when you add weight and reps, improving your performance can be a game changer in terms of increasing your muscle mass. If you’re able to lift longer and harder, your muscles will grow. Creatine is certainly a winner among muscle building supplements.
Homocyteine (normal serum range of 5-14µM) is known to adversely affect motor control in genetically susceptible people when their levels exceed 500µM, which is usually associated with genetically induced deficiencies of B12.[360][361] In these particular instances (assessed by rats fed homocysteine to increase serum levels to such a high level[362][363]) it appears that administration of 50mg/kg creatine (injections) to these rats can protect dysfunction in muscle metabolism (pyruvate kinase activity, Krebs cycle intermediates, and muscle cell viability) induced by homocysteine.[363]
Low testosterone or Low T can cause a number of symptoms in men (as well as women), and it may result from primary problems of the testicles or diseases affecting the parts of the brain that regulate the production of testosterone in the testicles. The normal range of testosterone in an adult male is between 300 and 1,100 nanograms per deciliter (ng/dL), with women having a much lower concentration. Levels of testosterone below 300 ng/dL are considered low in men. Testosterone in men usually peaks at the age of 30 after which it begins to fall gradually by 1% every year.

Before supplementation, our intramuscular pools of creatine and phosphocreatine are usually at about 70% of their full capacities. The levels of these pools can be raised by increasing dietary creatine. As vegans and vegetarians omit many creatine-rich foods, they tend to have lower creatine pools than omnivores and hence tend to benefit more from creatine supplementation. At the other end of the spectrum, creatine ingestion doesn’t increase creatine stores in a small proportion of people. It follows that these individuals don’t seem to experience the benefits of creatine supplementation.

In today's extra-large society, we tend to focus on the admirable guys who train hard and switch up their diet to transform their bodies by losing weight. We highlight their quests to lead healthier lives every chance we get — but there's another side of the wellness scale that can be just as difficult, depending on your body's makeup: Gaining mass and muscle.


Creatine is normally metabolized into creatinine (note the difference in spelling), which is eliminated by the kidneys under normal conditions. When the kidneys fail and cannot clear the blood as effectively, many metabolites get “backlogged” in the blood. Creatinine is easy to measure and as such it is a biomarker of kidney damage.[623][624] If serum creatinine levels are elevated, the doctor may suspect some kidney damage. Low-dose creatine (≤5 g/day) may not cause alterations in this biomarker in otherwise normal adults[524][625][525] but high doses of supplemental creatine may cause a false positive (an increase in creatinine, due to creatine turning into creatinine, which does not signify kidney damage) and is a diagnostic error.[520][518][626][523][517] Most studies, however, have noted only a small increase in creatinine levels even with doses ≈20 g/day.[524][626][627]


Creatine kinase enzymes (of which there are numerous isozymes) exist in both the mitochondria and the cytosol of the cell.[45][40] The four isozymes of creatine kinase include the Muscle Creatine Kinase (MCK), present in contractile muscle and cardiac muscle, and the Brain Creatine Kinase (BCK), expressed in neuron and glial cells and several other non-muscle cells. These two creatine kinases are met with Sarcolemmic Mitochondrial Creatine Kinase (sMitCK), expressed alongside MCK, and the ubiquitous Mitochondrial Creatine Kinase (uMitCK), which is expressed alongside BCK everywhere else.[25][39]
The majority of your workouts should be comprised of compound exercises. Common examples include squats, deadlifts, lunges, bench presses, rows, pull-ups, lat pull-downs, overhead presses, and so on. Isolation exercises should definitely also be a part of your program, just a smaller part in comparison. Common examples include bicep curls, tricep extensions, chest flies, lateral raises, leg curls, leg extensions, calf raises, and so on.
Unfortunately, it’s hard to significantly increase levels through food alone. That’s where supplementation comes in. For instance, in one 12-week study of resistance-trained individuals, taking HMB in tandem with a high-intensity lifting routine significantly improved muscle strength and size compared to lifting alone. Plus, in the off-chance that you push yourself too hard, HMB helps prevent the effects of overtraining—including muscle loss.
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