While the number of reps you do per set is important, of equal importance is the total number of reps you do per muscle group. The National Strength and Conditioning Association has determined that, to maximize growth, you need approximately 20–70 total reps per muscle group. Depending on which end of a rep range you’re working, this can be done in one session or over a few days (a training week, for instance), but that’s the spread you need to cover to see gains.
Testosterone is only one of many factors that influence aggression and the effects of previous experience and environmental stimuli have been found to correlate more strongly. A few studies indicate that the testosterone derivative estradiol (one form of estrogen) might play an important role in male aggression. Studies have also found that testosterone facilitates aggression by modulating vasopressin receptors in the hypothalamus.
How much of a difference does EPOC make? Well, in one research study of young women, basal metabolic rate spiked by 4.2 percent 16 hours following a strength-training session that lasted an hour and 40 minutes—the equivalent of burning an extra 60 calories, on average. That’s a long workout, and 60 extra calories isn’t exactly huge. Plus, EPOC is not a permanent boost. Research suggests it may last anywhere from 12 hours to a few days, depending on the workout and who is doing it. The calories you burn through EPOC can add up over time, especially if you’re lifting weights three or four times a week, but all in all, it doesn’t have a very big effect on your metabolism.
It was traditionally thought that total brain blood flow was not changed during physical activity. Research in the last 10 years, however, changed this perspective. We now understand that the increased neuronal and metabolic activity of the brain during exercise drive increases in blood flow to it. We have also learned that exercise that is too intense will reduce blood flow and oxygen delivery causing fatigue. So, what is the ideal intensity to stimulate blood flow to the brain, and perhaps, augment your mental abilities in the moment?
The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression". Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible. The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game. Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.
Cyclocreatine appears to be passively diffused through membranes and not subject to the creatine transporter, which can be beneficial for cases where creatine transporter function is compromised (creatine non-response and SLG6A8 deficiency). Similar to other forms of creatine, it buffers ATP concentrations, although its efficacy as a supplement in otherwise healthy people is currently unknown.
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. In these particular instances (assessed by rats fed homocysteine to increase serum levels to such a high level) 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.
It raised the question about performance-enhancing drugs. Their murky role in bodybuilding has long shrouded the sport. A 2013 documentary on Heath and Mr. Olympia called “Generation Iron” (a sort of bookend piece to 1977’s “Pumping Iron,” which launched Schwarzenegger and others to fame) called the topic “taboo.” It then insinuated that, of course, bodybuilders competing in top-level contests like Mr. Olympia use steroids.