Testosterone is important for maintaining muscle mass and strength, bone mass, fat distribution, sex drive, and sperm production in men.
Low testosterone associations include:
Decreased cognitive function
Lower libido - low sex drive
Increased breast size
Symptoms of low testosterone:
osteoporosis or fracture
lethargy or diminished physical performance are nearly universal, especially in older men.
Testosterone circulates almost entirely bound to transport proteins: Normally less than 1-2% is free. The principal transport protein for testosterone is known as sex hormone binding globulin (SHBG) or testosterone-estradiol binding globulin (TeBG). Testosterone measurements are used to assess erectile dysfunction, infertility, gynecomastia, and osteoporosis and to assess hormone replacement therapy.
Elevated estradiol levels in males may be due to increased aromatization of androgens, resulting in gynecomastia, (man boobs). There is a reason and it's not just exercise. If this concerns you have this test and see if you are in balance.