Muscle wasting and weakness are particularly attractive targets for intervention because they are related to loss of function and can be objectively measured and targeted for improvement. Small studies support the possible benefits of two strategies to increase muscle size and strength among patients on dialysis. Anabolic steroids were frequently used to ameliorate the anemia associated with end-stage renal disease prior to the introduction of recombinant erythropoietin, and these agents were noted to cause an increase in serum creatinine along with increases in hemoglobin and hematocrit. More recently, nandrolone decanoate has been shown to increase lean body mass and improve physical performance, and resistance exercise training has been shown to increase strength and improve physical performance. Neither of these preliminary results has been confirmed, nor have the relative benefits of these strategies or their potential additive or synergistic effects been examined. Therefore, we designed a study to compare changes in lean body mass, muscle size and strength, physical performance, and self-reported functioning over a12 week period among hemodialysis patients randomly assigned to one of four groups: 1) nandrolone decanoate, a synthetic testosterone derivative, by weekly intramuscular injection (ND); 2) weekly placebo injections (PL); 3) lower extremity resistance exercise training during dialysis sessions three times per week plus weekly placebo injections (EX); and 4) resistance exercise plus nandrolone injections weekly (EX+ND).