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.
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.
The basic principles of weight training are essentially identical to those of strength training, and involve a manipulation of the number of repetitions (reps), sets, tempo, exercise types, and weight moved to cause desired increases in strength, endurance, and size. The specific combinations of reps, sets, exercises, and weights depends on the aims of the individual performing the exercise.

Creatine supplementation may be able to enhance lifespan, secondary to increasing intracellular carnosine stores. Carnosine is the metabolic compound formed from beta-alanine supplementation, and in a mouse-model for premature aging (senescence-accelerated premature aging, SAMP8) creatine supplementation without any beta-alanine has been shown to increase cellular carnosine stores.[126] That being said, the aforemented SAMP8 study noted an increase in carnosine levels at middle age, but not old age in the mice.[126] A human study using 20g of creatine for one week in otherwise healthy people failed to find an increase in intracellular carnosine stores.[126]
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?

Although some have voiced concerns about kidney damage with creatine supplementation, it’s generally regarded as a safe supplement when taken responsibly. The Mayo Clinic advises against taking it if you have an allergy. When used properly, the incidence of potential side effects such as low blood sugar and dehydration, are minor in healthy people taking a safe dosage.
This is another thing I am very tired of hearing. 'No matter what I do or what I eat, I can't gain weight'. I have heard this countless times and I am here to tell you that you are dead wrong. That's OK, because I actually said the same thing until I realized the truth. Most people think they are eating a lot and you just may be. But no matter what you are eating, if you are not gaining, you are not eating enough. Most times, you should re-evaluate your diet as well and focus on more calorie dense foods. But you need to eat more if you are not gaining.
Most experts recommend starting with your larger muscle groups and then proceeding to the smaller ones. The most demanding exercises are those performed by your large muscle groups, and you will need your smaller muscles to get the most out of these exercises. But don't feel limited by that. You can do your exercises in any order you like, and changing the order is a great way to challenge yourself in different ways.
Creatine is most commonly found in the basic form of creatine monohydrate, which is the standard form and usually recommended due to the low price. It can also be micronized to improve water solubility, or the monohydrate can be temporarily removed to concentrate creatine in a small volume supplement. Neither alteration changes the properties of creatine.
Why it made the list: Whey tops the list of mass-gain supplements because it's the most crucial for pushing protein synthesis. Whey is a milk protein that has a high level of branched-chain amino acids (BCAAs, No. 4 on our list). Bottom line: Whey takes the crown because it digests fast and gets to your muscles rapidly to start building muscle. Whey also contains peptides (small proteins) that increase blood flow to the muscles. This is why we always recommend consuming whey protein immediately after training.
This suppression of creatine synthesis is thought to actually be beneficial, since creatine synthesis requires s-adenosyl methionine as a cofactor and may use up to 40-50% of SAMe for methylation[35][36][122] (initially thought to be above 70%, but this has since been re-evaluated[122]) though the expected preservation of SAMe may not occur with supplementation.[487] Reduced creatine synthesis, via preserving methyl groups and trimethylglycine (which would normally be used up to synthesize SAMe), is also thought to suppress homocysteine levels in serum,[37] but this may also not occur to a practical level following supplementation.[487]
Studies of so-called "smart drugs" have also been taken out of context. Some "smart" nutrients, available over the counter, are marketed as a way to "increase mental focus and concentration during training." The problem is that the studies they're based upon involved either animals or people with brain pathology. In normal people the effects of smart drugs remain unproven, except anecdotally.
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]
Peirano, R. I., Achterberg, V., Dusing, H. J., Akhiani, M., Koop, U., Jaspers, S., Kruger, A., Schwengler, H., Hamann, T., Wenck, H., Stab, F., Gallinat, S., and Blatt, T. Dermal penetration of creatine from a face-care formulation containing creatine, guarana and glycerol is linked to effective antiwrinkle and antisagging efficacy in male subjects. J.Cosmet.Dermatol. 2011;10(4):273-281. View abstract.
One pilot study using 150mg/kg creatine monohydrate for a five day loading phase followed by maintenance (60mg/kg) for the remainder of the five weeks noted that supplementation was associated with fewer muscle symptoms and complaints alongside improved muscular function,[572] yet a later trial trying to replicate the obsevations using 150mg/kg daily for five weeks noted the opposite, that creatine supplementation exacerbated symptoms.[573]