We’ll define the “bigger muscle groups” as being chest, back, quads and hamstrings, and the “smaller muscle groups” as being biceps, triceps and maybe abs. Shoulders are really somewhere in the middle, though I tend to lean more toward the “smaller” guidelines. Calves, while technically small, are another muscle group that is somewhere in the middle, and I can really go either way depending on the needs of the person.
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.
Most studies support a link between adult criminality and testosterone, although the relationship is modest if examined separately for each sex. Nearly all studies of juvenile delinquency and testosterone are not significant. Most studies have also found testosterone to be associated with behaviors or personality traits linked with criminality such as antisocial behavior and alcoholism. Many studies have also been done on the relationship between more general aggressive behavior/feelings and testosterone. About half the studies have found a relationship and about half no relationship.[66] However, later it was found out that testosterone activates dominant, aggressive behavior if at the same time a person has high testosterone and low levels of cortisol in the blood. Conversely, a high level of testosterone and high levels of cortisol do not stimulate dominant behavior. Because cortisol inhibits the action of testosterone.[67][68][69][70] This is probably why the results of the experiments were inconsistent.
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.
Gains will differ from one individual to another depending on body size and level of experience in the gym. To make sure you'’re gaining muscle, not fat, don'’t just consider your scale weight. Instead, rely on what you see in the mirror and use a tape measure twice a month to keep track of your waist and hips (you don't want to gain there)— as well as your biceps, chest and quads. Also, don'’t think that you have to gain a set amount of weight each and every week. "Your mass gain doesn'’t have to be uniform,"” Aceto explains. That means you can gain 1/2 pound one week and 1 1/2 the next, perhaps none the third week and still remain on course. "“Expecting uniform gains ignores the intricate makeup of the body and the way it gains mass -— or loses fat - which is by no means in linear fashion," adds Aceto.
It doesn’t get more natural than getting a good night’s sleep. Research published in the Journal of the American Medical Association showed that lack of sleep can greatly reduce a healthy young man’s testosterone levels. That effect is clear after only one week of reduced sleep. Testosterone levels were particularly low between 2 and 10 p.m. on sleep-restricted days. Study participants also reported a decreased sense of wellbeing as their blood testosterone levels dropped.
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 gluteus maximus arises from the posterior gluteal line of the inner upper ilium, and the rough portion of bone including the crest, immediately above and behind it; from the posterior surface of the lower part of the sacrum and the side of the coccyx; from the aponeurosis of the erector spinae (lumbodorsal fascia), the sacrotuberous ligament, and the fascia covering the gluteus medius. The fibers are directed obliquely downward and lateralward; The muscle has two insertions: Those forming the upper and larger portion of the muscle, together with the superficial fibers of the lower portion, end in a thick tendinous lamina, which passes across the greater trochanter, and inserts into the iliotibial band of the fascia lata; and the deeper fibers of the lower portion of the muscle are inserted into the gluteal tuberosity between the vastus lateralis and adductor magnus. Its action is to extend and to laterally rotate the hip, and also to extend the trunk.[citation needed]
Testosterone is necessary for normal sperm development. It activates genes in Sertoli cells, which promote differentiation of spermatogonia. It regulates acute HPA (hypothalamic–pituitary–adrenal axis) response under dominance challenge.[22] Androgen including testosterone enhances muscle growth. Testosterone also regulates the population of thromboxane A2 receptors on megakaryocytes and platelets and hence platelet aggregation in humans.[23][24]
Many athletes follow a "loading" protocol of around 25 grams a day for five days, but this isn't essential. But as Ciaran Fairman notes in the article "Do I Need to Load With Creatine," you can also get the same benefits with around 5 grams a day, potentially with none of the mild side effects of the loading protocol, which include stomach pain and water weight gain. The catch is that you have to take it consistently. Don't skip it!

The rise in testosterone levels during competition predicted aggression in males but not in females.[90] Subjects who interacted with hand guns and an experimental game showed rise in testosterone and aggression.[91] Natural selection might have evolved males to be more sensitive to competitive and status challenge situations and that the interacting roles of testosterone are the essential ingredient for aggressive behaviour in these situations.[92] Testosterone produces aggression by activating subcortical areas in the brain, which may also be inhibited or suppressed by social norms or familial situations while still manifesting in diverse intensities and ways through thoughts, anger, verbal aggression, competition, dominance and physical violence.[93] Testosterone mediates attraction to cruel and violent cues in men by promoting extended viewing of violent stimuli.[94] Testosterone specific structural brain characteristic can predict aggressive behaviour in individuals.[95]