For most athletes who select a variety of foods and meet their energy needs, supplements are not necessary. Choose...IronCalciumVitamin EVitamin D supplements are sometimes recommended for female athletes who may not get enough in their diets. The Choose...hypothalamusthyroidadrenal glandpituitary glandsynthesizes the testosterone precursors androstenedione and dehydroepiandrosterone (DHEA). Some claim that supplements of these two precursors will lead to increased testosterone levels and enhanced muscle mass. Researchers have found, however, that Choose...the supplements only raise testosterone levels in menthe supplements are more likely to raise testosterone level in womenthe supplements lower estrogen levels in womenthe supplements have no measurable effects on men. Taking large doses of Choose...creatinecaffeinesodium bicarbonatepyruvate as been shown to facilitate signals between the nervous system and the muscles. Its benefits are outweighed by the fact that the substance promotes water loss. Ginseng has become popular among athletes because reports suggest that it Choose...increases performance through increased staminadecreases an athlete’s perceived efforts during exercisefunctions as an antioxidant and spares vitamin Eleads to more androgen production and larger muscle mass. Several well-controlled studies have shown improvements in muscle strength when Choose...creatinecaffeinesodium bicarbonatepyruvate supplementation was added to a strength training regimen. But creatine supplements appear Choose...not to help with explosive power needed for sprintsto have no benefit for aerobic trainingto cause weight lossto lead to more estrogen production . In the mitochondria of muscle cells, actively helps transfer electrons in the electron transport chain.