Your basal metabolic rate (BMR)—the calories you burn just to live—is driven by a host of factors, including your sex, genetics, and age, Tim Church, M.D., professor of preventative medicine at Pennington Biomedical Research Center at Louisiana State University, tells SELF. Research published in the medical journal PLOS ONE also shows that the size of your internal organs plays a huge role in why some people burn more calories at rest than others—in fact, the study found that 43 percent of the differences between people’s metabolic rates can be explained by organ size.
A simple blood test can determine testosterone levels. There is a wide range of “normal” or healthy level of testosterone circulating in the bloodstream. The normal range of testosterone for men is between 250 and 1100 ng/dL for adult males, and between 8 and 60 ng/dL for adult females, according to the Mayo Clinic. Ask your doctor to test your testosterone levels if you have concerns about low testosterone (low T).
Researchers found that 5g of creatine four times daily for a week (loading) before sleep deprivation for 12-36 hours was able to preserve cognition during complex tasks of executive function at 36 hours only, without significant influence on immediate recall or mood.[279] A similar protocol replicated the failure to improve memory and attention, but noted less reports of fatigue (24 hours) and less decline of vigor (24 hours) although other mood parameters were not measured.[276]
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]