Cortisol is another hormone that needs to be deeply understood in order to maximize muscle gains and fat loss. Muscle gains and fat loss indirectly affects every athlete, in ever single sport; its not just for bodybuilders. If 2 boxers, the exact same height, with the same length arms, and the same skill level, get in the ring, whoever is in better shape wins, with all other things equal. Its not necessarily the absolute most important thing in every sport (like it is in football), but it affects nearly every sport.
Clearly if cortisol is essentially important for burning fat and/or building muscle, everyone from the soccer mom trying to lose weight to the nfl player should learn to appropriately handle it (decrease it).
Cortisol causes the human body to break down muscle for energy (when there is a energy defficiency[kcal burned exceeds kcal ingested]), and to build fat (when there is an excess). Cortisol’s function is as a stress hormone. Stress, evolutionarily, is frequently related to lack of food, so cortisol has your body break down muscle for fuel, when you don’t eat (so that humans can have energy during periods of starvation/fasting), and causes you to put on fat when you eat (to prepare for the next food shortage). It is pretty much unecessarily high in most people in modern times, because we don’t have food shortages.
The ways to limit cortisol are to limit physical stress, and limit mental stress. Stressing mentally (such as breaking up with a boyfriend or girlfriend) will elevate cortisol, and depending whether you forget to eat, or eat too much, you will gain fat or lose muscle. It’s really a lose/lose with cortisol no matter what quantity you eat, so you want to minimize the hormone. Trying to avoid mental stress is very important. Ironically, even though we are talking in an advanced way about hormones, eliminating physical stress is a very simple concept to explain. Limiting cortisol physically? Avoid unhealthy food, blood sugar spikes, trans fats, alcohol, caffeine, crack cocaine, methamphetamine, high fructose corn syrup… etc. You get the idea. Everything deemed “unhealthy” tends to raise cortisol.
Antioxidants, and things referred to as “anti-aging,” typically reduce cortisol.
Testosterone can be explained along with cortisol. This is because testosterone is the antithesis of cortisol, it causes the body to go into muscle building mode in caloric excesses, and causes the body to burn fat, and spare muscle, in times of lower kcal and higher activity levels. Charles Poliquin (a famous Olympic level trainer) frequently referrs to the most important hormone aspect being the T to C ratio. This is because high cortisol can outright subtract the beneficial effects of testosterone, and vice versa (Test, as far as muscles, can negate the negative actions of high cortisol). Someone with fairly average testosterone but very low cortisol might have above average muscle building genetics, despite not having high T (Testosterone).
Testosterone does, however, get more attention than it deserves, because anabolic steroids are testosterone, and derivatives of testosterone. However, without resorting to potentially unhealthy tactics, manipulating your testosterone level to be higher is not as easy as lowering cortisol (eating healthy, avoiding drugs/toxic food, staying hydrated etc). The most well known ways to increase T naturally are to make sure your vitamin D levels are adequate [cheap to do] (almost everyone’s D levels are inadequate in the U.S. and the colder parts of Europe except in the summer), and taking zinc (a non oxide form, preferably[cheap to do]), and to make sure a good magnesium supplement is being taken [possibly very expensive… I choose to eat nuts frequently instead of supplement it, foods are always higher bioavailability than supplements, so the same amount of magnesium is more effective]. Other ways to increase testosterone are having sex, lifting weights, and watching violent movies (just to give a physical feeling of what high T feels like). Just basically be a man.
Other than resorting to drug use, or herbal supplement use (basically the same thing; after all Cocaine and Heroin come from the ground, natural does not mean healthy), there are not many ways to significantly increase testosterone’s effects, other than lowering cortisol, and making sure to lift weights. Cortisol, however, can be significantly affected by diet and lifestyle, in a way where trainees who thought they had “bad genetics” will begin to think they have “good genetics.” (This has happened to me, and I realized, I dont have good genetics, I have just become good at fitness, and part of that is making sure I have high testosterone and low cortisol, which gives the appearance of good genetics… but in reality i am eating, sleeping, exercising, and supplementing my diet correctly, to create good genetics. Genetics, when used as a word by Gym rats, and “internet experts” that hide behind the keyboard with no real life accomplishments or pictures, is often just referring to a couple hormones.)