The design of the study is a standard double-blind design, which is needed in this study to allow for unbiased evaluation of efficacy and safety. The effect of the additional impact of testosterone replacement therapy in hypogonadal men on muscle strength and quality of life in comparison to physical exercise alone will be assessed. Treatment duration will be 54 weeks, to monitor the increase as well as the "steady state" of the parameters assessed.

Inclusion Criteria:

• Men aged 60 years and older (>60yrs), untrained
• Symptomatic hypogonadism as defined by a) and b)
• a) Total testosterone below 12 nmol/l (measurement 7.00-11.00 a.m.)
• b)Total Aging Males' symptom score above 36
• Willing to avoid significant change in the pattern of physical exercise and lifestyle for the duration of the study
• Residence in Cologne Area

Exclusion Criteria:

• Previous assignment to treatment during this study
• Use of androgen therapy or anabolic steroids respectively 12 months of entry into the study (i.e. screening visit/visit 1)
• Current participation in an exercise program or within the last 6 months
• Suspicion or known history of prostate or breast cancer or other hormone dependent neoplasia
• Abnormal finding on Digital Rectal Examination (DRE)
• Prostate specific antigen (PSA) level >4 ng/ml
• History of clinically significant post void residual urine (> 150 ml)
• Suspicion or known history of liver tumor
• Hypersensitivity to the active substances or any of the excipients of NEBIDO e.g. benzyl-benzoate and castor oil
• Blood coagulation irregularities presenting an increased risk of bleeding after intramuscular injections including vitamin-K-antagonists or other strong anticoagulants
• 32 Additional Exclusion Criteria