Fast twitch (or Type II fibers) fire very quickly, but also fatigue quickly, so they don’t last long.  It gets a bit more complicated, because there are actually two types of fast twitch fibers. Type IIA fibers have some endurance qualities (used for things such as longer sprints). While Type IIX fibers are our “super fast” fibers, used only when a super short burst is needed (like a 100 m sprint or a really heavy lift).
Recently, studies are coming out that show a general decline in testosterone levels of men in the United States and around the world. The trend is across the board and doesn’t appear to be caused simply by a decline in health, aging or an increase in obesity rates. It could be caused because of chemicals or environmental factors. In any case, low levels of testosterone can affect many areas of your health, including your ability to build muscle. If you suspect that you have low testosterone levels, you can ask your doctor to test you for it. In addition to traditional hormone therapies, there are also many natural ways to boost your levels including through supplements, some of which will be discussed later in this article.
Generally, you should consume about 20 grams of protein with some carbs shortly after a workout. During the post-workout anabolic window, you’ll also want to limit fats, which can slow the absorption of protein. While there is some recent research that suggests the window may actually extend up to several hours following exercise, there’s no harm in getting nutrients in early as long as you’re sticking to your overall caloric and macronutrient goals.
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’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.
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]
Although creatine is a natural component of food, the amount of food required to supersaturate the muscle with PCr may not be feasible. For example, it could require 22 pounds of meat daily [8]. If creatine monohydrate is proven to be a safe and effective ergogenic aid, creatine supplementation may be the simplest way to increasing muscle stores. It may be beneficial to avoid caffeine if taking creatine supplements. One study showed that caffeine diminished strength gains seen with creatine use [9].
The creatine transporter (CrT) is positively regulated by proteins known to be involved in sensing and responding to the cellular energy state, including the mammalian target of rapamycin (mTOR[158]). Upon activation, mTOR stimulates SGK1 and SGK3[159][160] to act upon PIKfyve[161] and subsequently PI(3,5)P2[162] to increase CrT activity.[161] Beyond mTOR, SGK1 also is stimulated by intracellular calcium[163] and a lack of oxygen (ischemia).[164] Because transient ischemia is associated with increased reactive oxygen species (ROS) production after blood flow is restored (reperfusion) it has been hypothesized that muscle contraction may increase creatine uptake through a similar ROS-mediated mechanism.[165]

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]

Cornelissen, V. A., Defoor, J. G., Stevens, A., Schepers, D., Hespel, P., Decramer, M., Mortelmans, L., Dobbels, F., Vanhaecke, J., Fagard, R. H., and Vanhees, L. Effect of creatine supplementation as a potential adjuvant therapy to exercise training in cardiac patients: a randomized controlled trial. Clin.Rehabil. 2010;24(11):988-999. View abstract.
Isometric exercise provides a maximum amount of resistance based on the force output of the muscle, or muscles pitted against one another. This maximum force maximally strengthens the muscles over all of the joint angles at which the isometric exercise occurs. By comparison, weight training also strengthens the muscle throughout the range of motion the joint is trained in, but only maximally at one angle, causing a lesser increase in physical strength at other angles from the initial through terminating joint angle as compared with isometric exercise. In addition, the risk of injury from weights used in weight training is greater than with isometric exercise (no weights), and the risk of asymmetric training is also greater than with isometric exercise of identical opposing muscles.
Legion’s Recharge is a good pick for muscle growth. Besides the creatine itself, it contains a hefty 2.1 grams of l-carnitine l-tartrate, which has solid links with improving muscle repair in addition to increasing focus during workouts. It’s also delicious, naturally sweetened, and it contains ingredients that may improve insulin sensitivity and help the body to better utilize carbs for recovery.

Great Paleo beef protein, why? Because it doesn't have any preservatives, fillers, Dairy, soy, yeast, corn, or any other additives. No artificial colorings/flavorings. That makes this product not just paleo, but also autoimmune paleo friendly, hard to find. That basically means anti alergic, you dont get the same digestive issues many people get with whey. I think beef protein is underrated, I just finished a batch and went back to my whey. The whey gives me bloating/gas that this product doesnt. Also if you don't like how the amino acid profile stacks up agains Whey protein powder you can add some BCAA to powder, at least thats what I do. In a 30 gram saving you get 28 grams of protein (zero fat and zero carb), not bad!

Despite the fact that BCAAs may offer some benefits, you should keep in mind that these three amino acids are also present in any quality whey protein that you purchase. You can also get these essential amino acids from food sources. Basically, as long as you’re meeting your daily protein intake goals, you’re probably getting enough of these essential amino acids. Research supports this approach. So, why spend more on another supplement?
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.[158] Consistent with the well-known role of AMPK as a suppressor mTOR signaling,[177] CrT activity has also been shown to be inhibited in response to AMPK activation in kidney epithelial cells.[178] Since AMPK suppresses mTOR via upstream TSC2 activation,[179] 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.[178] This pathway seems to max out at around 30% suppression, with no combination of mTOR antagonists and AMPK inducers further suppressing creatine uptake.[178]
The specific mechanism of intestinal uptake for creatine is not clear, although transporters have been identified in rat jujenum, and confirmed at the mRNA level in humans.[129][130] The observation that creatine can be absorbed against a concentration gradient to a max ratio of 8:1 (8 times more creatine in the intestinal cell post absorption, relative to the lumen) supports transporter-mediated uptake, and the dependence on sodium and chloride implicate SLC6A8 (Creatine Transporter 1) as the operative transporter.[102]

To succeed and thrive as a bodybuilder, it takes more than overwhelming muscular strength or athletic prowess. Judges select bodybuilding champions based on muscle mass, definition, proportion, symmetry, and an athlete’s stage presence. Given the criteria, it is no surprise that most serious bodybuilders consider supplementation to be an essential component of their training regimen.
When assessing type I muscle (slow twitch) against type II muscles (fast twitch) in response to creatine supplementation, it seems that glycogen accumulation may only occur in the latter as assessed in rats,[359] where the soleus muscle is a model for slow twitch muscle fibers and the gastrocnemius is a model for fast twitch. This is similar to human creatine distribution, which seems to accumulate in type II muscles rather than type I.[367]
If you’re new to training, then check out some of the options found on the site and run them exactly as the author intended them to be executed. Too many young guns want to alter every training variable rather than running the program as written and focusing on getting stronger. No, you don’t need an entire day dedicated to arms when you can’t even complete a single chin-up.
You burn calories during strength training, and your body continues to burn calories after strength training (just like you do after aerobic exercise), a process called "excess post-exercise oxygen consumption" or EPOC, according to the American Council on Exercise. (13) When you do strength, weight, or resistance training, your body demands more energy based on how much energy you’re exerting (meaning the tougher you’re working, the more energy is demanded). That means more calories burned during the workout, and more calories burned after the workout, too, while your body is recovering to a resting state.
When creatine is increased in the fetus (from maternal supplementation of 5% creatine), the fetus has a greater chance of survival and increased growth rates to a level not significantly different than vaginal birth.[531] Protection from hypoxia has also been noted in the offspring’s diaphragm (through preserved muscle fiber size),[533] kidneys,[534] and neural tissue (due to less oxidation in the brain and less cellular apoptosis).[535]
Macrophages are known to express creatine kinase[290] and take creatine up from a medium through a sodium dependent mechanism (likely the creatine transporter) in a saturable manner,[435] with a second component that requires there to be no concentration gradient to work against (likely passive diffusion) but this effect tends to only account for up to 10% of total uptake in the physiological range (20-60µM).[435] Supraphysiological range was not tested.
When you’re doing higher reps, focus on the muscle you are trying to build and squeeze every ounce of effort out of it. Yes, cheesie as it may sound, visualizing the muscles working and growing while you train them can be helpful. A 2016 study in the European Journal of Applied Physiology found that, when lifters thought about their pecs and triceps during a workout, they activated them better.
Creatine monohydrate is the most common form of creatine, and if not otherwise mentioned is the default form of creatine used in most studies on creatine.[64] It has fairly decent intestinal absorption[65][12] (covered more in depth in the pharmacology section) and is the standard form or “reference” form of creatine, which all other variants are pitted against.

It can be hard to know where to start when beginning strength training. There are countless exercises you can do, some of which work some muscles, but not others. There are safety concerns to beware of, a wide variety of sometimes confusing equipment to help you in your efforts, and so on. With some familiarity of the basics of getting started with strength training, actually doing so can become far less daunting, and you can begin to craft a routine that is targeted toward helping you achieve your personal goals.
Tribulus Terrestris: A fruit from the Mediterranean, this supplement has been used in the Indian traditional medicine of Ayurveda. In addition to helping increase testosterone, many people take it to increase libido and as a cardioprotective aid. (10) Unfortunately, despite the fact that there are claims that tribulus terrestris can increase testosterone levels, studies don’t back up these claims.  There is some evidence, however, that it may improve athletic performance. If you want to choose one of the supplements for men, this should be your pick.

The 1960s saw the gradual introduction of exercise machines into the still-rare strength training gyms of the time. Weight training became increasingly popular in the 1970s, following the release of the bodybuilding movie Pumping Iron, and the subsequent popularity of Arnold Schwarzenegger. Since the late 1990s increasing numbers of women have taken up weight training, influenced by programs like Body for Life; currently nearly one in five U.S. women engage in weight training on a regular basis.[4]
Supplementation of creatine at 5g daily alongside rehabilitation (after limb immobilization for two weeks while taking 20g daily) is associated with a preservation in GLUT4 levels, which were reduced during immobilization. During exercise rehabilitation, it increased to 40% above placebo.[330] This study failed to note an increase in GLUT4 in control, despite exercise normally doing so.[331][332] This effect is thought to be the result of the low frequency of activity. Thus, creatine was thought to augment the increase (insignificant due to low exercise) to significant levels.[330] In other studies, creatine was found to increase GLUT by approximately 30% relative to control, but this effect failed to reach statistical significance. This study did not issue an exercise protocol.[207]
Branched-chain amino acids (leucine, isoleucine, valine) play important roles in muscle building. Some researchers have found that following exercise, the branched-chain amino acids, especially leucine, increase the rate of protein synthesis and decrease the rate of protein catabolism (Blomstrand, 2006). The billion dollar supplement industry has been quick to respond; leucine supplements are widely available in health food stores, with a cost upwards of $50 per container. However, because the research findings are inconsistent and little is known about the safety of these products, the American Dietetic Association (soon to be renamed the Academy of Nutrition and Dietetics) advises against individual amino acid supplementation and protein supplementation overall (Rodriquez, 2009). It may be that food sources of these proteins and amino acids provide the same effect for a small fraction of the cost.
Arginine mainly benefits the body in two ways. The first of these is by producing nitric oxide. When arginine enters the body, some of it gets converted into nitric oxide. Nitric oxide is important for regulating blood pressure, as it can enlarge the blood vessels. Larger blood vessels allow the body to increase blood flow throughout the body, bringing extra nutrients and oxygen to the muscles during exercise.
^ Jump up to: a b c d e f g h Momaya A, Fawal M, Estes R (April 2015). "Performance-enhancing substances in sports: a review of the literature". Sports Med. 45 (4): 517–531. doi:10.1007/s40279-015-0308-9. PMID 25663250. Wilson et al. [91] demonstrated that when non-resistance trained males received HMB pre-exercise, the rise of lactate dehydrogenase (LDH) levels reduced, and HMB tended to decrease soreness. Knitter et al. [92] showed a decrease in LDH and creatine phosphokinase (CPK), a byproduct of muscle breakdown, by HMB after a prolonged run. ... The utility of HMB does seem to be affected by timing of intake prior to workouts and dosage [97].