What Is the Impact of Testosterone on Muscle Mass?

What Is the Impact of Testosterone on Muscle Mass?

Direct and Indirect Anabolic Effects

Steroids have been synthesized over the years, but there is still some uncertainty about how steroids impact muscle mass. Currently, direct activation of the cellular androgen receptor and induction of protein synthesis are known as the main modes for anabolic actions of all anabolic/androgenic steroids. We can increase the rate at which muscles hold on to proteins by boosting our androgen levels from outside sources through testosterone supplementation or similar anabolic steroids.

This therefore is the principal reason why muscles grow when people use anabolic/androgenic steroids. With increasing hormone levels comes enhancement in the activation of AR and ultimately, protein synthesis. However, other indirect mechanisms besides this common understanding of androgens’ effects on protein metabolism may influence muscle growth. An indirect mechanism does not involve binding to the androgen receptor, yet it may involve altering other hormones that are a consequence of changing local hormone concentrations or the release of locally acting factors that could induce cell growth (perhaps through other membrane-bound receptors).

It is important to note that muscle mass disposition also depends on other things such as protein breakdown, and nutrient transport. We can’t forget masculinizing action on those factors either. As for the first, testosterone studies show that this hormone does not stimulate amino acid uptake by tissues. This probably explains the intense synergy between insulin, a very active hormone that strongly helps in nutrition transportation into muscles for bodybuilders; however, it confirms increased protein degradation associated with anabolic steroid use. Nonetheless, one should realize the second way by which androgens could affect muscle growth.

Testosterones Anti-Glucocorticoid Effect

Testosterone (and other synthetic anabolic/androgenic steroids) can promote gains in weight and power through its anti catabolic effect in skeletal muscle fiber cells. These hormones are considered to be one of the most vital indirect mechanisms of androgen action affecting yet another kind of steroid hormone present in the human body – glucocorticoids (cortisol being its main representative). Instead of decreasing glucocorticoid effects on muscle cells unlike what androgens do thus instructing stored proteins to release themselves.

Catabolism is a process, which involves breaking down of muscle tissue. Thus, when the anabolic effects of testosterone are more pronounced than its degenerative effects as well as cortisol; you will experience muscle growth. However, during intense training and a proper diet, the body usually tends to store more protein than it removes while this fixing battle occurs throughout. Yet, in such times and cases where anabolic steroids are administered, there can be much higher levels of androgens that can place glucocorticoids at a significant disadvantage. In the long run, fewer cells will be instructed to release more proteins because the effect has been minimized while others will accumulate.

The main underlying factor behind this effect is believed to be the androgen displacement of glucocorticoids bound to the glucocorticoid receptor. It should also be noted that even in vitro studies have demonstrated a high affinity of testosterone for this receptor supporting some direct mediation of its anabolic activity through this route. There is also a suggestion that these hormones indirectly interfere with DNA binding to glucocorticoid response elements (GRE). Nonetheless, it is clear that steroid administration inhibits protein breakdown during the fasting state; thus strongly indicative of anti-catabolic properties regardless of whether they are being contested.