Although cutting out egg yolks is sometimes recommended for dieters because they are high in calories, the yolks can be beneficial in a number of ways. One way in which egg yolks can provide benefits for athletes is by enhancing levels of testosterone. Several nutrients in egg yolks may be conducive to promoting increased testosterone levels, but egg yolks aren't recognized as a dietary supplement or a cure for any condition, so your results may vary.
Many people eat egg whites, rather than whole eggs, because the yolks contain all of the fat in eggs. However, this fat can be beneficial if you want to increase your testosterone levels. A study published in "The American Journal of Clinical Nutrition" found that increased fat intake promoted increases in testosterone levels.
Egg yolks are rich in the mineral calcium. Calcium is an important nutrient, often found in dairy products, that can help maintain the strength of your bones and teeth. Additionally, a study published in the "Biological and Trace Element Research" explains that calcium may help increase testosterone levels.
Egg yolks are a rich source of vitamin D. This vitamin helps promote proper immune function and regulates calcium levels. Additionally, research from the journal "Hormone and Metabolic Research" indicates that increased vitamin D intake can produce higher testosterone levels.
Because egg yolks are high in protein, they are also rich in amino acids, which are the building blocks of protein. Eggs are particularly rich in aspartic acid, an amino acid which research from the "Reproductive Biology and Endocrinology" found could significantly increase testosterone levels in just 12 days.