The first session will be performed prior to the initiation of testosterone therapy and the second session will be performed after receiving testosterone for 7 days. Because dietary intake, particularly protein intake, can influence muscle metabolism, subjects will be placed on standardized diets for the twenty four hour period preceding muscle metabolism studies in order to reduce the likelihood of skewed results due to variations in nutritional intake just prior to these studies. In addition, subjects will be asked to maintain a food intake diary for the three day period prior to metabolism studies in order to document dietary intake in the days leading up to muscle metabolism studies. Subjects will also be asked to complete a fatigue questionnaire at baseline and at the final study to assess perceived changes in fatigue between the two treatment groups over the treatment period. Subjects will also collect their urine over a twenty four hour period prior to baseline and final studies to measure cortisol levels, which can influence the rate of protein breakdown.