Workouts lasting longer than about an hour may begin to spike cortisol levels and subsequently decrease testosterone. Additionally, research has demonstrated that a shorter rest period between sets (1 minute versus 3 minutes) elicited higher acute hormonal responses following a bout of resistance training.11 To maximize your testosterone response, keep your rest periods short and total workout time to 60 minutes or fewer.
The researchers found that the dose of testosterone required to produce different effects in the body varied widely. The influence of testosterone and estradiol also differed. As the testosterone gel dose was reduced, the scientists showed, reductions in lean mass, muscle size, and leg-press strength resulted from decreases in testosterone itself. In contrast, increases in body fat were due to the related declines in estradiol. Both testosterone and estradiol levels were associated with libido and erectile function.
A large number of side-effects have been attributed to testosterone. In our clinical experience, the incidence of significant adverse effects with treatment producing physiological testosterone levels is low, and many side effects attributed to testosterone are mainly relevant to supraphysiological replacement. Some adverse effects are specific to a given mode of delivery and have already been described. Potential adverse effects concerning the prostate have also been discussed and require appropriate monitoring of symptoms, PSA and digital rectal examination. Other tumors which may be androgen responsive include cancer of the breast and primary liver tumors, and these are both contraindications to testosterone treatment
[quote]You see there is a difference between your free testosterone levels and your total testosterone levels. As testosterone flows through your blood, free testosterone is chemically active and available for your body to use as it will. While other testosterone is floating around bound to SHGB (Sex Hormone Binding Globulin). This testosterone is inactive and unable to be used by your body because the SHGB renders it inert. So while you may have a high amount of “total testosterone,” much of it may be unavailable to be used by your body. So it is really the amount of free testosterone in your body that you should be concerned with.”[/quote]
There is increasing interest in the group of patients who fail to respond to treatment with PDE-5 inhibitors and have low serum testosterone levels. Evidence from placebo-controlled trials in this group of men shows that testosterone treatment added to PDE-5 inhibitors improves erectile function compared to PDE-5 inhibitors alone (Aversa et al 2003; Shabsigh et al 2004).
Testosterone levels generally peak during adolescence and early adulthood. As you get older, your testosterone level gradually declines — typically about 1 percent a year after age 30 or 40. It is important to determine in older men if a low testosterone level is simply due to the decline of normal aging or if it is due to a disease (hypogonadism).