Hormones are powerful things; they affect everything. Different hormones, of course, directly affect different things. Here’s what you need to know about testosterone.
Testosterone, popularly known as the male sex hormone, is present in both men and women (but in amounts averaging ten times higher in men) as an anabolic (promoting growth) steroid hormone. In men, it is made in large amounts in the testicles; in women, it is made in smaller amounts in the ovaries; and in both men and women, small amounts in the adrenal glands.
Testosterone is essential for the development of male reproductive tissues, but has many secondary roles in both men and women: it helps build muscle, burn fat, boost energy, increase strength, increase bone density, lift depression, increase sex drive, and more. In women, higher levels of testosterone are associated with higher levels of assertiveness.
Testosterone can affect fat metabolism:
Testosterone is a muscle building hormone, and muscle helps you burn more calories at rest, while also giving the body a tighter, more compact shape.
Testosterone blocks the effects of lipoprotein lipase, an enzyme that enables the body’s fat cells to store fat. Testosterone also increases fat metabolism by increasing certain key receptors on the fat cell-membrane to release fat. (See article) Through this mechanism, testosterone also increases insulin sensitivity.
*One study suggests that weight loss makes fat men more masculine by preserving testosterone; fat cells synthesize the enzyme aromatase which converts testosterone, the male sex hormone, into estradiol, the female sex hormone (estogen); a decrease in fat cells would lead to a decrease in the synthesis of aromatase, responsible for this phenomenon.
Things that affect testosterone levels in both sexes:
Aging lowers levels of testosterone, along with other factors such as poor diet, alcohol consumption, smoking, caffeine, excess body fat, and stress. It has been suggested that inadequate levels of Vitamin D are associated with decreased levels of testosterone in men.
A nutritious diet, especially one rich in vitamin A, zinc, magnesium, and B6, healthy omega-3s (fish oil, chia seed), and especially amino acids (the building blocks of protein) will promote testosterone production. This is accomplished by eating a variety of fresh vegetables, complete proteins, and healthy fats in the form of nuts, seeds, and olive oil. Watching fat intake is key, as the Standard American high-fat Diet lowers testosterone levels. When seeking complete proteins, watch fat content, as animal-based saturated fats tend to be stored (as fat*, see above), whereas monounsaturated fats (nuts, olives, avocado) and polyunsaturated fats (omega 3s) are used preferentially for fuel.
The incorporation of resistance training–weight bearing exercise–into your fitness program is essential for increasing levels of this slimming hormone. Compound exercises are better than isolated exercises, as they recruit more muscle fibers. Lifting heavier encourages more testosterone production that high-rep, light-weight endurance lifting.